Additionally, abnormal hematological results of blood cell counts and coagulation function tests in adult secondary HLH patients were found, with a median hemoglobin level of 78.00 (67.00, 89.75) g/L, median leukocyte count of 1.87 (1.07, 4.01) × 109 /L, median platelet count of 39 (18, 65) × 109 /L, median prothrombin time of 13.85 (12.20, 16.65) s, and median fibrinogen level of 1.23 (0.80, 1.91) g/L. Here, F2 is linked to hemophagocytic syndrome.