One of the initial clinical studies showing autologous IFN-γ producing CD4 T cell transfer as an effective therapeutic agent in cancer patients was performed by Hunder et al. Using an autologous CD4 T cell clone with specificity to the melanoma-associated antigen NY-ESO-1, these investigators showed that transferred tumor-reactive IFN-γ-producing CD4 T cells mediated a durable clinical remission and promoted endogenous responses against melanoma antigens other than NY-ESO-1 in a melanoma patient (Hunder et al., 2008). Here, CD4 is linked to melanoma.