ABCB5 and melanoma: Interestingly, ABCB5 is a novel drug transporter and a chemoresistance mediator identified in human melanoma and instinctively present in a subset of chemoresistant, stem cell phenotype-expressing tumor cells among melanoma bulk populations, indicating that these chemoresistant cells can be specifically targeted via ABCB5 to enhance cytotoxic efficacy [69].