SLC39A6 and esophageal cancer: Interestingly, common polymorphisms in other zinc transporters show genome-wide associations with disease traits, such as a non-synonymous variant in the zinc efflux transporter ZnT8 (SLC30A8) and diabetes incidence [54], as well as a regulatory variant in the zinc influx transporter ZIP6 (SLC39A6) and survival in esophagal cancer [55].