Immunological staining was conducted in 120 primary cutaneous melanoma to determine the clinical value of c-Ski and SnoN expression levels. A significant association was observed between nuclear c-Ski and SnoN expression with ulcerated tumors and high Breslow tumor thickness. SnoN was also correlated with the presence of metastatically invaded sentinel lymph node. These findings suggest that c-Ski and SnoN are involved in the progression and growth of melanoma and may also play a relevant role in the resistance of melanoma against TGF-beta regulated growth control (Boone, B. et. al. J Dermatol Sci 2009, 53[1]: 26).