May play a pivotal role in the detoxification of heavy metals such as cadmium but do not depend exclusively on phytochelatins (PC) synthesis. Expressed in coelomocytes, as well as in head and tail neurons, and in the intestinal cells. RNAi-mediated knockdown causes hypersensitivity to Cd(2+) and exhibit Cd(2+)-elicited changes in cellular morphology. Even at the lowest Cd(2+) concentrations they arrest in the early larval stages and eventually die. The intestinal epithelial cells of hmt-1 RNAi worms upon exposure to toxic levels of Cd(2+) elaborate punctate refractive inclusions within the vicinity of the nucleus. Belongs to the ABC transporter superfamily. ABCB family. Heavy Metal importer (TC 3.A.1.210) subfamily.