We have also reported the presence of the gray phenotype, caused by a germline intronic duplication in STX17 that activates the MAPK pathway56, and the 11 bp ASIP exon 2 deletion (Fig. 1 and Supplementary Data 1), both previously linked to the regulation of coat coloration and a higher incidence of melanoma in horses56. The gene discussed is ASIP; the disease is melanoma.