John York has stepped down as the chair of the NFL's international committee to become chair of the newly created health and medical committee, commissioner Roger Goodell announced this week.York, the 49ers' co-chair, will lead the new committee on health and medical issues. York, a pathologist, began his business career in 1982 as founder of DeYor Laboratories in Youngstown, Ohio.He received a doctorate in blood pathology from Stritch School of Medicine at Loyola University Chicago in 1975. He spent seven years of post-doctoral study, specializing in the laboratory diagnosis of lymphoma and leukemia.Jerry Jones (Cowboys), Rich McKay (Falcons), John Mara (Giants) and Mark Murphy (Packers) will be the other members of the new Health and Safety Advisory Committee."Our committee structure has been very important and beneficial to the NFL over the years," Goodell said. "It has allowed us to address and study complex issues in depth and present our clubs with comprehensive information and thoughtful recommendations."Clark Hunt (Chiefs) is taking over as the chair of the NFL's international committee.