PROS1 and liver disorder: In addition to advanced liver disease, acquired causes of protein S deficiency include any cause of disseminated intravascular coagulation, l-asparaginase, warfarin, cancerous condition, and acute severe bacterial infections, etc. In our practice, we do not routinely apply anticoagulant or anti-PLT in patients with PVT, but according to thrombus size, extension, degree of the occlusion, EV degree, bleeding history, recent episode, and risk of deterioration.