Human ABCB1 transporter was the first recognized ABC transporter: its overexpression in cancer cells reduces the concentration of drugs in the cell and allows it to develop resistance to a number of chemotherapic drugs (Table 1), such as taxanes (paclitaxel), vinca alkaloids (vinblastine), and anthracyclines (daunorubicin) [40]. Here, ABCG2 is linked to cancer.