KIT and metastatic melanoma: One year after the initial surgical resection of the melanoma from the right foot, patient 2 was found to show metastatic melanoma in his right thigh, and the genetic mutations of c-KIT and PDGFRA showed that a novel mutation c.1936T>G in c-KIT exon 13, causing the production of missense amino acid mutation p.Y646D (Figure 3A).