S100A9 and cancer: One of these is S100 calcium-binding A8 [S100A8; also called myeloid-related protein (MRP)-8 or calgranulin-A], which binds to S100 calcium-binding protein A9 (S100A9; also called MRP-14 or calgranulin-B) to form polymers, which serve a role in inflammation and cancer 22.