ABCG2 and cancer: All of these help the few cancer cellsto colonize a distant organ and transform it into a secondary infectionsite.81,82 During the EMT, cancer cells develop radiationresistance and chemoresistance which make cancer treatment more challenging.83−85 The ABC transporter protein is the major molecular component thatpumps out the drug from the cancer cells, and as a result, it leadsto drug resistance in cancer.