Since MAGE-D2 protects melanoma cells from tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis, this observation is of particular note, as TRAIL is involved in the killing of melanoma cells by the immune system and is expressed by a number of immune cells, including activated CD4 and CD8 T lymphocytes, natural killer cells and dendritic cells (32). This evidence concerns the gene CD4 and melanoma.