KITLG and melanoma: Functional analysis of the soluble form of KITLG (sKITLG) showed that mutant sKITLG (Asn36Ser) increased the content of melanin by 109% compared with wild-type sKITLG in human melanoma cells, and a gain-of-function effect of this missense mutation was indicated to possibly trigger hyperpigmentation of skin in patients [3].