Cytochrome P450 (CYP) enzymes which are expressed at higher levels in tumors of the digestive tract, liver, kidney, and brain, play a significant role in the MDR against vincristine, taxanes, etoposide, vinblastine, ifosfamide, doxorubicin, irinotecan, and cyclophosphamide [24]. The gene discussed is PPIG; the disease is neoplasm.