On the other hand, from genetic analysis the CDKN2AB homolog appears to be involved as an autosomal genetic determinant of melanoma in some of the Xiphophorus melanoma models, but since it is overexpressed, CDKN2AB does not appear to play a role in Xiphophorus melanoma analogous to the CDKN2A/ARF locus in human melanoma. This evidence concerns the gene CDKN2A and melanoma.