Compared with adriamycin (ADM) treatment alone, the rate of apoptosis of Eca109/ABCG2 cells treated by combination of EGCG with ADM for 24 h enhanced ADM concentration in the cancer cells, suggesting that EGCG can reverse multi-drug resistance by reducing the expression of ABCG2 and increase the concentration of drug in cancer cells to enhance the anticancer effects [46]. This evidence concerns the gene ABCG2 and cancer.