To increase the test specificity, it is advisable to perform a simultaneous analysis of S100 with other melanocytic differentiation proteins, such as MelanA (MART-1) melanoma antigen recognized by T cells, and glycoprotein 100 (gp100, pre-melanosome protein 17 (Pmel 17), SILV) [19,22,23]. The gene discussed is PMEL; the disease is melanoma.