PROS1 and hereditary antithrombin deficiency: The condition of hypercoagulability may be precipitated by a number of factors, including major surgery, trauma, pregnancy, sepsis, inflammatory syndromes (such as inflammatory bowel disease, systemic lupus erythematosus, and antiphospholipid syndrome (APS)), dehydration, estrogen therapy, and inherited thrombophilia (such as factor V Leiden, prothrombin mutation, protein C, protein S, and antithrombin deficiency) [1].