MPO and hematologic disorder: In addition, hematological disorders may also be related to polymorphisms in genes encoding xenobiotic-metabolizing enzymes, such as cytochrome P4502E1 (CYP2E1), myeloperoxidase (MPO), NAD(P)H:quinone oxidoreductase 1 (NQO1), and glutathione S-transferase (GST) [3–6].