In many diseases, including cancer, coronary atherosclerotic heart disease, psychosis, and depression, the protein product of SERPIND1, heparin cofactor II (HCII), plays an important role in preventing the onset of disseminated intravascular coagulation in several thromboses, including deep vein thrombosis (Hoogendoorn et al., 2004; Noda et al., 2002; Rein et al., 2011). The gene discussed is SERPIND1; the disease is depressive disorder.