ABCG2 and cancer: Among the primary causes of MDR, overexpression of ABC transporters in cancers diminished the remission of chemotherapy.[51] The gradually increased number of anticancer drugs were identified as the substrates of ABCG2 and overexpression of ABCG2 was recognized to be closely related to the resistance of these drugs, necessitating the development of a novel treatment for ABCG2-mediated MDR.[52,53]