John Kane became a partner in 1980, and focused his practice on litigation, emphasizing health care matters, until his retirement on December 31, 2007.

John's practice included substantial involvement in medical peer review matters (including related litigation arising as a result of physician discipline), and he participated in numerous programs and seminars on the subject of physician peer-review and related confidentiality issues. John handled matters arising under the determination of need laws, and resulting from reimbursement disputes. He also represented Health Maintenance Organizations in licensure matters, benefit disputes, and a lawsuit under a state "any willing provider" statute. He participated in lawsuits involving hospital mergers, including actions brought to obtain judicial approval of such mergers. His practice included a wide range of general litigation, including labor (discrimination), product liability matters, contract disputes, and real estate disputes. He represented hospitals in connection with investigations by the Massachusetts Attorney General under Chapter 93A of the Massachusetts General Laws.

John is a Trustee and former member of the Board of Managers of the Massachusetts Eye and Ear Infirmary. In addition, he was been the firm's designated representative since 1985 to the CPR Institute for Dispute Resolution, a preeminent national forum on alternative dispute resolution comprised of leading corporations, law firms, judges, and academics. He also conducted programs and provided advice on alternative dispute resolution, and represented clients in several mediations.