However, vitamin K1 may also induce thrombotic complications, such as a popliteal deep vein thrombosis (Franco et al., 2013) and intracranial venous thrombosis (Papin et al., 2007), likely due to early depletion of anticoagulant proteins C and S (Lipton and Klass, 1984). The gene discussed is PROC; the disease is deep vein thrombosis.