(ARA) – Multiple myeloma (MM) is a relatively rare type of blood cancer that affects white blood cells. Approximately 20,000 patients are diagnosed with MM in the United States each year, including Geraldine Ferraro, the first female Vice Presidential candidate for a major US political party, and actor Roy Scheider, made famous for his role in Jaws.

MM accounts for 13% of all hematological, or blood, cancer cases. Below are five things you need to know about this disease.