Parrot et al. reported that intra-melanoma DP T cells were transcriptome-wise closer to CD8+ SP T cells [34], while Mucida et al. found mature CD4+ T helper cells could undergo transcriptomic re-programming and generate cytotoxic CD4+CD8+ DP T cells after persistent ovalbumin antigen stimulation [35]. This evidence concerns the gene CD4 and melanoma.