Collagen receptor involved in collagen-induced platelet adhesion and activation. Plays a key role in platelet procoagulant activity and subsequent thrombin and fibrin formation. This procoagulant function may contribute to arterial and venous thrombus formation. The signaling pathway involves the FcR gamma- chain, the Src kinases (likely Fyn/Lyn), the adapter protein LAT and leads to the activation of phospholipase C gamma2. Defects in GP6 are the cause of bleeding disorder platelet-type 11 (BDPLT11). BDPLT11 is a mild to moderate bleeding disorder caused by defective platelet activation and aggregation in response to collagen. 3 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.