ABCB6 and cancer: Multi-drug-resistant (MDR) cancers trafficxenobiotic drugs fromwithin the cell to the extracellular space via a range of active transportprocesses broadly termed drug efflux.1,2 Predominantlyfacilitated by the adenosine triphosphate binding cassette (ABC) superfamilyof transport proteins, drug efflux ultimately lowers the intracellularconcentration of drugs and, in the case of effluxed chemotherapeutics,results in diminished efficacy.