The decreased expression of RORα and RORγ during progression of melanocytic lesions and the significant reduction of their expression in most advanced primary melanomas (Breslow thickness >2mm, Clark level III-V, pT3-4, pN1-3, overall stage II-IV) and melanoma metastases suggest that reduced or lack of RORα and RORγ expression or defects in the ROR pathways could promote tumor progression. This evidence concerns the gene RORC and melanoma.