C-Type Lectin Domain Family 3 Member B (CLEC3B) is a serum and tissue protein and it contais a C-type lectin which binds to Ca++. CLEC3B is originally found in plasma, the concentrations approximately 10mg/l. It can bind to kringle 4 of plasminogen and enhance the activation of plaminogen to plasmin, catalyzed by tissue plasminogen activator in the presence of poly-D-lysine. In addition, CLEC3B may be involved in the packaging of molecules destined for exocytosis. Also, CLEC3B is best known as a prognostic marker in ovarian cancer.