GSTM1 and lymphoma: During a period of (suspected) recurrence of lymphoma and EBV viremia (with negative serum EBV-IgM), he developed fever, splenomegaly, severe pancytopenia (Hb 3.8 mmol/L, thrombocytes 0 × 109/L, leukocytes 0.1 × 109/L), and elevated ferritin (87,000 μg/L), elevated triglycerides (4.09 mmol/L) and increased soluble IL2 receptor (> 7500 U/ml).