The presence of both herpes viruses was associated with high risk clinical parameters (long duration of febrile neutropenia (more than 10 days) (p = 0.080), ANC < 0.8×109/l (p = 0.023), lymphopenia (< 0.5 ×109/l) (p = 0.008), thrombocytopenia (Plt < 96 ×109/l) (p = 0.137), and low Hb level (< 9.1 g/dl) (p = 0.010), more than patients negative for herpes viruses. This evidence concerns the gene GSTM1 and neutropenia.