There were no statistically significant differences among gender, median age, clinical features (fever, mean maximum temperature, hepatomegaly, splenomegaly, lymph node enlargement, rash, jaundice, edema, bone marrow hemophagocytosis) and laboratory data (ferritin, Epstein Barr virus (EBV) DNA, fibrinogen (FIB), ANC, HB, platelets, ALT, aspartate aminotransferase (AST), lactate dehydrogenase (LDH), DB, TG, albumin, Ca2+) between different subgroups within the test cohort, so we use the whole instead of subgroups to make further analysis. Here, ALB is linked to Hemophagocytosis.