SERPINE1 and thrombophilia: Due to limited resources, the following thrombophilia-related factors were unavailable: protein S and C activity assays, methylenetetrahydrofolate reductase (MTHFR) gene mutation analysis, factor V Leiden (FVL) testing, prothrombin G20210A mutation screening, and plasminogen activator inhibitor-1 (PAI-1) activity measurement.