KIT and gastrointestinal stromal tumor: In our skin melanoma cohort, similar to GIST, the most frequently mutated KIT exon is exon 11, although at lower frequency than in GIST (44.7%) followed by exon 9 (21.1%) and the other three exons (e13, e17, e18) with significant rates, suggesting a much broader carcinogenic targeting in melanoma.