TYR and melanoma: One is that modified tyrosinase substrates such as the sulfur homologue of tyrosine, cysteinylphenol (CP), and its amine analogue cysteaminylphenol (CAP), will be selectively incorporated into melanoma cells through active transport on the cell surface, which we believe can be used as the basis for developing a novel DDS (Figure 9) [29,30].