GSTM1 and isolated hyperferritinemia: Our case satisfied the required criteria (5/6 tested) for the diagnosis of HLH such as persistent high grade fever, bicytopenia (Hb < 90 g/L, ANC < 1000/cmm), splenomegaly in the absence of focal lesions, hyperferritinemia, and histiocytic hemophagocytosis in the bone marrow.