SLC39A3 (solute carrier family 39, member 2), is a 314 amino acid acid multi-pass membrane protein that localizes to the cell membrane and belongs to the ZIP family of zinc transporters. Two isoforms of ZIP3 exist as a result of alternative splicing events. ZIP3 is involved in translocation of extracellular zinc into a variety of cell types. Tumorigenic prostate epithelial cells contain less intracellular zinc than non-tumorigenic prostate epithelial cells. Loss of the ability to maintain zinc accumulation may be caused by the decrease in the ZIP1 protein expression and the intracellular redistribution of ZIP3.