GSTM1 and anemia: Univariate Cox regression analysis of five laboratory variables and nine imaging variables indicated that severe anemia (Hb<30 g/L), severe thrombocytopenia (PLT<50×109/L), severe CNS involvement, hepatic interstitial edema, heterogeneous liver/spleen enhancement, and massive ascites were significantly associated with poor outcomes in children with HLH (Table 3).