Immune thrombocytopenia: SLE, HCV, CLL; drug-induced: quinine, quinidine, trimethoprim/sulfamethoxazole, vancomycin, penicillin, rifampin, carbamazepine, ceftriaxone, ibuprofen, mirtazapine, oxaliplatin, suramin, heparin, Gp2a/3b inhibitors, ADP receptor antagonists; microangiopathic hemolytic anemia: TTP, HUS, HELLP, DIC; post-transfusion purpura; passive alloimmune thrombocytopenia. Here, P2RY1 is linked to thrombotic thrombocytopenic purpura.