John Mark Williams, 62, of Hopkinton, MA, died suddenly and unexpectedly of a heart attack on Sunday, September 20th. He was the son of John P. and Norma J. Williams of Martinsville, IN. He was born April 25th, 1953 in Indianapolis, IN. After earning a B.S. degree at Ball State University and Ph.D. at Indiana University, John moved to the Boston area to pursue a career in the field of immunology. He was Senior Vice President, Translational Medicine, at Genzyme Corporation. John was a loving, generous, and dedicated family man. He will be sorely missed by his family, friends, and all who had the pleasure of knowing him. He lived his life in the present, with a unique sense of humor, and sought fun and adventure each day. The true definition of a Team Player, John always strived to help others succeed, and fostered a supportive environment that would benefit as many as possible. He never clamored for the spotlight, and took pride in seeing his plans succeed as he stood quietly in the background. In that way, he was a rare and special man. He enjoyed cycling, cooking, and daily walks with the family dogs. He was an avid reader, and a talented amateur photographer. He was devoted to his wife, Diane (Platoniotis) Williams, and their two children, Miranda Michelle (22) and Logan Michael (19). He supported the girls' love of all things horses, and Logan's interests in flying, cars, cycling, and shooting. In addition to his wife, children, and parents, John leaves behind his sister Lisa, her husband Brian West, and nieces Krista and Ashley Borja, all in Indiana. Other family members who will miss John terribly include in-laws, Margaret and Thomas Platoniotis, sister-in-law Georgia P. Wiley, her husband Michael Wiley, nephews Kalen and Breslin, and niece Alexa (all in VA), Koumbara Mary Scoumis (PA), and favorite Uncle James Downey, his wife Donna, and their extended family (CA). A Celebration of John's Life will take place on Tuesday, September 29th at 4:00 PM in the Chapel of the Matarese Funeral Home, 325 Main Street, Ashland, MA 0172 (no black attire, please). In lieu of flowers, donations may be made in John's memory to the Central Caribbean Marine Institute, http://reefresearch.org/donate/, for preservation of the reefs that he and his family loved so much. Alternatively, donations may be made in his memory to the Walden Woods Project, https://www.walden.org/.