This gene encodes a putative cation-selective ion channel with two repeats of a six-transmembrane-domain. The protein localizes to lysosomal membranes and enables nicotinic acid adenine dinucleotide phosphate (NAADP) -induced calcium ion release from lysosome-related stores. This ubiquitously expressed gene has elevated expression in liver and kidney. Two common nonsynonymous SNPs in this gene strongly associate with blond versus brown hair pigmentation.[provided by RefSeq, Dec 2009].