HIT, particularly type 2, is an autoimmune-like reaction in which antibodies bind to platelet factor 4 (PF4)/heparin complexes that activate platelets via their FcγIIa receptors, resulting in thrombocytopenia, hypercoagulability, and greatly increased risk of arterial or venous thrombosis [3]. This evidence concerns the gene PF4 and Thrombocytopenia.