In the landmark phase III trial demonstrating an OS benefit to melanoma patients treated with ipilimumab (a CTLA-4 antagonist antibody), Hodi et al. found no added benefit when a gp100 peptide vaccine was added.141 This was likely due to the use of a short peptide vaccine, which we now know has low potency compared to other vaccine technologies. This evidence concerns the gene PMEL and melanoma.