ABCB5 and cancer: Several studies revealed ABCB5 exported doxorubicin, camptothecin, 10‐OH camptothecin, 5‐fluorouracil (5‐FU), paclitaxel and caffeic acid phenethyl ester (CAPE) to confer chemoresistance in subset of cells expressing cancer stem cell phenotypes including melanoma and HCC.7, 18, 21, 22, 23, 24