Its role as a molecular marker in melanoma patients was first proposed by Smith et al (1991) in the early 1990s; since then, tyrosinase expression has been applied for the detection of malignant melanoma cells in sentinel lymph node biopsies and investigated in peripheral blood, bone marrow and biological fluids (Ghossein et al, 1998; Blaheta et al, 2001; Hoon et al, 2001). This evidence concerns the gene TYR and melanoma.