May act by engaging a cell surface molecule on immature T-cells in the embryonic thymus. Plays a central role in mediating key epithelial-immune interactions by being involved in the selection of Vgamma5(+)Vdelta1(+) T-cells, which constitute 90% of epidermal gammadelta T-cells. Expressed in skin and thymus. The strain FVB/NTac displays a selective deficiency for epidermal Vgamma5(+)Vdelta1(+) T-cells due to a mutation that creates premature codon stop at position 324. Encoded by one of the 11 copies of Skint genes clustered in the D1 region of the chromosome 4. Humans and chimpanzees have a SKINT1-like (SKINT1L) gene with multiple inactivating mutations. All hominoid species have a common inactivating mutation, but that Old World monkeys such as olive baboons, green monkeys, cynomolgus macaques and rhesus macaques have apparently functional SKINT1L sequences, indicating that SKINT1L is inactivated in a common ancestor of hominoids. Belongs to the SKINT family.