IL2 and hemophagocytic syndrome: Given the cytopenia, elevated ferritin (> 1000 ng/mL (reference range: 21.8–274.7 ng/mL), elevated IL-2 (> 4000 pg/mL, reference range: 175.3–858.2 pg/mL), low natural killer cell activity, splenomegaly, and hypertriglyceridemia, the patient met 6 of 8 criteria for hemophagocytic lymphohistiocytosis (HLH) [17].