Many cytokines function by modulating the immune system to eliminate aberrant cells, thereby preventing the occurrence of cancer.40,191–193 One significant cytokine in cancer therapy is IL-2, which regulates and activates various immune cells, including T, B, NK, and dendritic cells.194 High-dose IL-2 has been approved by the FDA for the treatment of metastatic kidney cancer in 1992 and metastatic melanoma in 1998.195,196 Its therapeutic efficacy is attributed to its ability to stimulate the immune system and enhance the activity of immune cells. This evidence concerns the gene IL2 and metastatic melanoma.