Marlee Matlin's dad has cancer. Don Matlin is battling multiple myeloma, a cancer of the bone marrow. The 80-year old is undergoing chemotherapy. Her mother, Libby, and sister-in-law Gloria have both fought cancer. Matlin will take part in the Stand Up 2 Cancer telethon tomorrow. The TV special will also features Michael Douglas, who recently went public with his didagnosis of throat cancer.