Table 3.

S100 proteins and their roles in melanoma.

S 100 Protein	Roles and Main Target Proteins in Melanoma	References
S 100B	Higher expression in metastatic than primary melanoma tumors	[145]
	Used as prognostic marker and indicator of therapeutic responses	[62,65]
	Extracellular S100B activates RAGE	[60,105,113,146]
	Intracellular S100B prevents p53 activation	[147,148,149]
S 100A1	Higher expression in melanoma tumors than benign nevi	[150,151]
	Could modulate melanoma tumor growth through its interaction with RAGE and TRPM-1	[152,153,154]
S 100A2	Lower levels in metastatic than primary tumors A tumor suppressor role has been suggested, but the overall role is complex	[144,155,156,157]
S 100A4	Stimulates melanoma metastasis through RAGE activation Alters endothelial cell integrity	[158,159]
S 100A6	Higher expression in metastatic tumors than in benign nevi Up-regulation in RAGE overexpressing tumors Interacts with RAGE	[142,146,156,160,161]
S 100A8/A9	Higher levels in metastatic than in primary tumors Potential prognostic marker and predictor of survival Promotes lung metastases through the interaction with RAGE and S100 Soil Sensor Receptors (SSSRs)	[162,163,164]
S 100A13	Possible role as angiogenic and prognostic marker Facilitates secretion of angiogenic marker FGF Participates to dacarbazine resistance	[144,165,166,167]
S 100P	Higher levels in metastatic melanoma than in primary tumors and nevi Could promote melanoma metastasis through the interaction with ezrin (intracellular S100P) and RAGE (extracellular S100P)	[168,169]