The normocoagulable state in severe COVID-19 cases was associated with lower fibrinogen (median [IQR], 551 [481–579] mg/dL vs. 428 [359–534] mg/dL, adjusted P value = 0.03), lower platelet count (median [IQR], 246 [194–308] × 103/μL vs. 154 [126–204] × 103/μL, adjusted P value <0.001), and lower complement C3 value (median [IQR], 116 [100–128] mg/dL vs. 96 [73–118] mg/dL, adjusted P value = 0.05) (Table E3 in Additional File 1). The gene discussed is C3; the disease is COVID-19.