Joanna Lin focuses her practice on high-stakes corporate transactions and governance matters for public and private companies. Recognized by clients as a “world-class” and “uniquely intuitive” advisor who “can see around corners,” she brings deep experience in mergers and acquisitions (M&A), strategic transactions, and as board-level counsel, particularly in complex scenarios such as advising special committees, conflict transactions, cross-border transactions (with experience spanning more than 25 jurisdictions), and joint ventures.
- Represented Delta Electronics, Inc., a global leading provider of smart energy-saving solutions, in its acquisition of Universal Instruments Corporation, a global leader in precision automation solutions for smart manufacturing
- Represented strategic buyers in approximately 30 acquisitions of other accounting firms or professional services firm targets in the last five years
- Represented JLL (NYSE: JLL) in its joint venture with Slate Asset Management to commercialize a technology platform for commercial real estate
- Best Lawyers in America, Mergers and Acquisitions Law, 2024-2026
- Thomson Reuters, Stand-out Lawyer, 2024-2025
- Chambers USA, Corporate/M&A, Band 5, 2023-2025
- Legal 500 US, Recommended, 2022, 2024-2025
- IFLR1000, M&A, 2022-2023
- Euromoney, Americas Women in Business Law Mergers & Acquisitions Lawyer of the Year, 2022
- Texas Lawyer, Most Effective Dealmaker, 2022
- The M&A Advisor, Emerging Leaders and International M&A Awards M&A Deal of the Year, 2019
- American Bar Association Mergers and Acquisitions Committee, Women in Mergers and Acquisitions Subcommittee, co-chair
- Helms Hope Foundation, board member
- Boston College Law School, JD, cum laude
- University of California, Irvine, BA
- Texas
- Massachusetts
- Englisch
- Chinese (Mandarin)

Gregory E. Fosheim
Gregory (Greg) E. Fosheim provides counsel on a wide array of corporate, transactional and regulatory compliance matters across the healthcare and life sciences industry. Drawing on his extensive laboratory and public health background, he regularly advises on clinical and diagnostic laboratory matters, anatomic pathology and fertility laboratory compliance. Greg represents hospitals, health systems and physician practice management companies in all aspects of transactional and operational matters, particularly those with regulatory, licensing, accreditation and policy considerations. He has also negotiated several acquisitions and sales of proton therapy centers.
- Counseled a health system in navigating a complex, multi-million dollar unwind and settlement arrangement with another health system where it was the sole corporate member.
- Advised a gastroenterology physician practice management platform in its expansion efforts.
- Guided several cancer centers in the acquisition and sale of proton therapy equipment.
- Best Lawyers in America, Healthcare Law, 2025-2026
- Legal 500 US, Next Generation Partner in Healthcare: Service Providers, 2024-2025
- Best Lawyers: Ones to Watch in America, Healthcare Law, 2021-2024
- Legal 500 US, Rising Star, 2021 to 2022
- Law360, Healthcare Editorial Advisory Board, 2025
- American Health Lawyers Association
- Illinois Association of Healthcare Attorneys
- National LGBTQ+ Bar Association Board of Directors
- Lesbian and Gay Bar Association of Chicago
- Georgia State University College of Law, JD, magna cum laude, Order of the Coif
- Emory University, MPH
- Luther College, BA
- Georgia (inactive)
- Illinois

Diego E. Gómez-Cornejo
Diego Gómez-Cornejo focuses his practice on complex domestic and cross-border business transactions, with an emphasis on the representation of multinational companies and private equity firms in connection with mergers and acquisitions (M&A), divestitures, investments and other commercial activities. He also advises both publicly-traded and privately-held companies (including portfolio companies of private equity firms) on matters relating to corporate finance, venture capital and growth equity investments, recapitalizations, joint ventures, securities offerings, corporate governance and general corporate advice. He takes a thoughtful and proactive approach in supporting clients at all stages of transactions and has experience drafting and negotiating a wide spectrum of commercial contracts. Diego is also a frequent speaker and contributor to legal publications on M&A-related matters.
- Represented CenterGate Capital, L.P. in its acquisition of Mid-State Holdings, Inc., a leading provider of on-site and off-site industrial maintenance and service solutions, and multiple add-on transactions and financing-related issues
- Represented PharmaLex GmbH, a portfolio company of AUCTUS Capital Partners, a Munich-based private equity fund, in connection with multiple add-on transactions and financing-related issues
- Represented Steward Health Care System in the acquisition and divestiture of medical practices and health plans
- The Legal 500 USA, Recommended Lawyer, 2022
- Super Lawyers, Texas Rising Star in Mergers & Acquisitions 2016 to 2021
- Texas Minority Counsel Program, Steering Committee Member, 2017 to 2021
- American Bar Association, Mergers and Acquisitions Committee, member
- Hispanic National Bar Association, member
- SMU Dedman School of Law, JD, s, cum laude
- University of Texas at Arlington, umma cum laude, Honors BA
- Texas
- Englisch
- Spanish

Wilson Chu
Boardrooms and C-suites look to Wilson Chu to be their strategic advisor for his collaborative, creative, and business-minded approach.
Wilson focuses his practice on strategic transactions, particularly mergers and acquisitions (M&A), and governance for Fortune 500 serial acquirors to high-profile technology companies in the United States and abroad. While he has experience in a wide range of industries, his practice is heavily weighted in technology, particularly involving artificial intelligence-driven innovation, and is built on a foundation of repeat business from discriminating strategic acquirors.
Multiple acquisitions and strategic transactions for
- 7-Eleven, Inc.
- AmerisourceBergen Corporation (NYSE: COR)
- Dell Inc. (NASDAQ: DELL)
- Jones Lang LaSalle (NYSE: JLL)
- Renren, Inc. (NYSE: RENN)
- Sabre Corporation (NASDAQ: SABR)
- Xerox Corporation (NYSE: XRX)
- United States Automobile Association
- Varian Medical Systems
- Best Lawyers in America, Corporate Law, International Mergers and Acquisitions, Mergers and Acquisitions Law, 2007-2026
- Chambers USA, Corporate/M&A, 2025
- Thomson Reuters, Stand-out Lawyer – independently rated lawyers, 2025
- The Legal 500 US, Recommended, 2023
- Co-Founder, Alliance for Asian American Justice
- PracticalLaw.com, member of advisory board
- Asia M&A Forum, co-organized by the Inter-Pacific Bar Association and Euromoney’s International Financial Law Review, founding conference chair
- The University of Texas Mergers & Acquisitions Institute, founding co-chair
- Dallas Bar Association, Mergers & Acquisitions Section, founding chair
- SMU Dedman School of Law, JD
- Southern Methodist University, BBA
- Texas
Jacques Buhart
Jacques Buhart, based in the Firm’s Paris and Brussels offices, focuses his practice on corporate M&A and EU competition. He is the founder of the Firm’s Paris office, which counts now about 100 lawyers.
On the M&A side, Jacques advised Mitsubishi Heavy Industries in the restructuring of the French nuclear industry and acquisition of interest in Framatome and Orano as well as attempt with Siemens to bid for Alstom; Metsaliitto in its acquisitions and divestments in the EU; TUI is its acquisition of Transat France and Nidec in the creation of a joint-venture with Peugeot and Fujitsu in the acquisition of a French cloud company. Jacques also advised Arriva in the privatization of rail transport in France.
Jacques has handled a broad range of complex competition matters. In the merger field, among others, he represented Cellnex in challenging the joint- venture between Vodafone and Télécom Italia, Mitsubishi Hitachi Power in challenging the acquisition of Alstom by GE; TotalFina in its acquisition of Elf (second phase); Metsä-Serla in the sale of its carbonless paper division to Arjowiggins (second phase) and in the notification of SCA’s acquisition of Metsä Tissue (second phase); and Atos Origin in its acquisition of Banksys.
- The Best Lawyers in France, 2025
- The Legal 500 EMEA, Belgium: Competition: EU and Global, France: EU, Competition and Distribution, 2023-2024
- IFLR1000, M&A, 2022-2023
- Who’s Who Legal, Recommended, M&A and Governance, Competition, 2021
- Chambers Europe, Competition/European Law-Belgium
- Paris 1 Panthéon-Sorbonne University, LLM (DESS), Diploma of the Institute of Comparative Law
- Hague Academy of International Law, JD
- Paris-Panthéon-Assas University, MBA
- Institute of Comparative Law
- École Supérieure de Commerce de Paris (ESCP)
- Brussels
- Paris
- Englisch
- Französisch

Hamid Yunis
Hamid Yunis advises clients on complex areas of transactional law (M&A, Investments, Private Equity, Major Projects and Corporate Finance) predominantly within the health industry and on infrastructure transactions. He has substantial global experience in innovative structures for complex joint ventures, public-private partnerships and funding arrangements. Hamid’s global client base includes health care providers, medical products manufacturers and organizations establishing “medical cities”, along with non-health clients where he advises on infrastructure projects and major projects. Hamid also has a particular interest in advising Sovereign Wealth Funds on their investments and other transactions.
Hamid joined McDermott from a leading international law firm based in London where he spent over 14 years and was head of the firm’s Health Care Group.
- Advised Varian Medical Systems on a number of transactions in the UK, Europe and Asia. Some of these were structured as PPP arrangements. In particular, Hamid acted for Varian on the negotiation and financial close of the contract relating to the major supply of proton beam therapy equipment and the supply of associated maintenance services in the UK (UCLH and The Christie)
- Advised C&C Alpha Group on various investor funding rounds and on the sale of London International Hospital
- Acted for Johns Hopkins Medical International on the establishment of a Joint Venture in China for a number of clinics
- The Best Lawyers in the United Kingdom, Healthcare Law, 2023-2025
- Legal 500 UK, Recommended, 2022–2025
- Chambers UK, Healthcare: Corporate/Commercial, 2022–2025
- The Lawyer, Hot 100, 2023
- Who’s Who Legal, Healthcare, 2021
- Chambers UK, Banking & Finance (Islamic Finance), 2021
- Chambers Europe, UK: Banking & Finance (Islamic Finance), 2020
- Chambers Global, UK: Banking & Finance (Islamic Finance), 2018
- Law Society of England and Wales
- The University of Law – Chester, LLB, Honours
- England and Wales

James Ross
James Ross advises clients on a broad range of international and domestic corporate/commercial tax issues, including corporate restructuring, transfer pricing and thin capitalisation, double tax treaty issues, corporate and structured finance projects, mergers and acquisitions, and management buyouts. He counsels US groups in the structuring of UK and European inbound investments, including in relation to redomiciliations and providing advice on technical issues in the context of revenue investigations and statutory audits. He is particularly adept at advising on intellectual property holding structures.
- Advised US-based multinationals on restructuring their British and European groups, and on the implementation of corporate redomiciliations and UK holding company structures
- Advised European-based multinationals on the establishment of functions and activities in the UK
- Advised multinational groups on structuring for optimising the management and holding of intellectual property
- Chambers UK 2021 and 2022, ranked within Tax and described as „a great lawyer who is responsive and knowledgeable.„
- The Legal 500 UK 2012 to 2022, recommended in Corporate and Commercial: Corporate Tax
- World Tax and World Transfer Pricing 2013 to 2020
- Bloomberg BNA Tax Treaties Analysis, editorial board
- University of Law, LPC
- University of Law, CPE, BA
- Jesus College University of Oxford
- England and Wales
Michael P. Chu
Michael P. Chu focuses his practice on all aspects of patent law, including complex litigation, opinions and prosecution. He serves as the Local IP Litigation Practice Group Leader in McDermott’s Chicago office. Mike is also the head of the Firm’s Racial & Ethnic Diversity Committee.
- Representing hospital and researchers relating to immunotherapeutic treatments and medical devices (Immunomedics, Inc. v. Roger Williams Medical Center et al., Civ. Action No. 2:15-cv-04526 (D.N.J. 2015-present))
- Obtained an award of attorney fees and dismissal in client’s favor in patent infringement lawsuit relating to papermaking processes (Nalco Co. v. Solenis LLC, Civ. Action No. 1:15-cv-008913 (N.D. Ill. 2015-2017))
- Represented defendant in lawsuit brought by supplier and obtained stay in favor of international arbitration (Key Tronic Corporation v. SMART Technologies ULC Civ. Action No. 2:16-cv-00028-TOR (E.D. Wa. 2016-2017))
- Sought a temporary restraining order against an importation port to prevent loss of trademarked goods from China; the case successfully settled in the client’s favor (WesPac International, LLC v. Apex Maritime, Inc., Civ. Action No. 1:14-CV-01579 (N.D. Ill.))
- Represented complainant Eastman Kodak Company in the pending ITC investigation relating to infringement of Kodak patents for digital imaging technology; the case successfully settled (Certain Electric Devices for Capturing and Transmitting Images, ITC No. 337-TA-831 (2011-2013))
- IAM Patent 1000 – The World’s Leading Patent Practitioners, 2021-2024
- Chambers USA, Intellectual Property, 2021-2026; Band 2, 2024-2026
- Best Lawyers in America, Litigation – Intellectual Property (2016-2023, 2025-2027), Trademark Law (2023-2027), Litigation – Patent, Patent Law, 2026-2027
- Legal 500 USA, Recommended Lawyer, 2022 and 2024-2025
- Crain’s Chicago Business, Notable Leaders in Community Development, 2022
- American Bar Association
- National Asian Pacific American Bar Association (NAPABA), president, 2003
- NAPABA Law Foundation, president, 2009 to 2012
- Asian Americans Advancing Justice – Chicago, board chair, 2011 to present
- Chicago Committee on Minorities in Large Law Firms, board chair, 2016
- William & Mary Law School, JD
- University of Illinois at Urbana-Champaign, BS, Mechanical Engineering
- Illinois
- US Court of Appeals for the Federal Circuit
- US District Court for the Northern District of Illinois
- US Patent and Trademark Office
- Supreme Court of Illinois
- Englisch
- Chinese (Mandarin)
Rebecca Waltuch
Advising on a wide range of transactional and regulatory matters, Rebecca (Becca) Waltuch counsels hospitals, health systems, accountable care organizations (ACOs) and other healthcare clients through complex operational and contracting matters, including multi-state physician practice acquisitions, joint ventures and provider employment agreements. Becca advises clients on structuring transactions and navigating any health regulatory issues that arise in such transactions. Becca is also experienced in addressing the legal issues that arise in establishing or restructuring physician network affiliations, value-based payment models and managed-care contracting.
- Serves as the lead lawyer for a large hospital system in the sale and acquisition of physician practices.
- Counsels on all regulatory and transactional aspects of multiple community hospital acquisitions and strategic affiliation deals in the for-profit and nonprofit sectors.
- Advised a large health system on the formation and operation of a Next Gen ACO, a MSSP ACO and a Medicaid ACO, including the preparation of certain fraud and abuse waivers.
- Best Lawyers in America, Healthcare Law, 2023-2025
- American Health Lawyers Association
- Diversity and Inclusion Committee and Gender Diversity Subcommittee at McDermott
- Northeastern University School of Law, JD
- Tufts University, MPH
- Barnard College, BA
- Massachusetts
- New Jersey
- New York

Sarah E. Walters
Sarah Walters is a former federal prosecutor and experienced trial lawyer who focuses her practice on white-collar criminal defense, regulatory enforcement and compliance matters and complex civil litigation. In addition to both criminal and civil trial work, Sarah has substantial experience conducting internal investigations and representing clients in securities, healthcare and other government enforcement matters. She also assists companies in developing compliance policies and programs.
Government and Internal Investigations
- Defends a broad spectrum of organizations, including healthcare providers and systems, government contractors and publicly traded companies, in connection with civil and criminal government investigations and related litigation
- Represents executive of major publicly traded company in FCPA investigation
- Represents government contractor in False Claims Act investigation related to compliance with cyber security requirements
- The Best Lawyers in America, Criminal Defense: White-Collar and Litigation – Securities, 2019 to 2024
- The Best Lawyers in America, Lawyer of the Year, Criminal Defense: White Collar, Boston, 2023
- The Best Lawyers in America, Lawyer of the Year,Litigation – Intellectual Property, Boston, 2024
- Chambers USA, Litigation: White-Collar Crime & Government Investigations, 2021 to 2023
- Legal 500 US, 2019
- Boston College Law School, JD, magna cum laude, Order of the Coif 1997
- University of Pennsylvania, BA, cum laude
- Massachusetts
- US Court of Appeals for the First Circuit
- US Court of Appeals for the Fourth Circuit
- US District Court for the District of Massachusetts
