KRT15 and metastatic melanoma: KRT1, KRT2, KRT5, KRT6A, KRT6B, KRT6C, KRT10, KRT14, KRT15, KRT16 and KRT17 were all highly expressed in primary melanoma in both TCGA and GSE47517 cohort (P < 0.001); however, KRT8 was overexpressed in metastatic melanoma in TCGA cohort.