Among them, ABCB1 (P-gp/MDR1), ABCCs (MRPs) and ABCG2 (BCRP/MXR/ABCP) are the main members of the ABC transporters related to MDR in tumor cells (Arrigoni et al., 2016; Obreque-Balboa et al., 2016). The gene discussed is ABCG2; the disease is neoplasm.