The protein encoded by this gene is a zinc efflux transporter involved in the accumulation of zinc in intracellular vesicles. This gene is expressed at a high level only in the Pancreas, particularly in islets of Langerhans. The encoded protein colocalizes with insulin in the secretory pathway granules of the insulin-secreting INS-1 cells. Allelic variants of this gene exist that confer susceptibility to diabetes mellitus, noninsulin-dependent (NIDDM). Several transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Mar 2010]