MUC16 and cancer: Increased serum levels of CA125 (Whitehouse and Solomon, 2003), a mucin-type protein (Lloyd et al. 1997) that is often secreted into the blood by ovarian cells shed by cancer cells or also made by inflamed normal cells that line body parts, is widely used in the clinical setting to monitor ovarian cancer patients for early diagnosis of tumor recurrence (Bast et al. 1998) and follow-up of patients after treatment to calculate response (Rustin et al. 1999).