MTHFR and pulmonary embolism: Turan et al. evaluated 90 patients diagnosed with pulmonary embolism by conducting thrombophilia screening, which included screening for mutations of Factor V Leiden, prothrombin G20210A, methylenetetrahydrofolate reductase C677T-A1298C, and antithrombin III and serum levels of protein C, protein S, factor VIII, and activated protein C resistance.