PMEL and melanoma: Interestingly, spontaneous responses to peptides derived from proteins such as tyrosinase [15, 73], gp100/pmel17 [19, 74, 75], Melan-A/MART-1 [76, 77], gp75/TRP1 [78], or TRP2 [79] are frequent in melanoma patients and healthy donors [80, 81], suggesting that central tolerance to these antigens is not complete.