GSTM1 and Pancytopenia: In the 5th week, she developed daily spiking fevers and progressive laboratory abnormalities matching with HLH, showing elevated ferritin (up to 13.542 μg/L), elevated triglycerides (up to 3.46 mmol/L), mildly decreased fibrinogen (1.2 g/L) and pancytopenia (Hb 6,4 mmol/L, thrombocytes 37 × 109/L and neutrophils 0.0 × 109/L).