IL2 and neoplasm: Immune therapies have been developed to actively and specifically stimulate the host immune system using cytokines including high-dose interleukin (IL)-2 [1]; molecular vaccines targeting tumor-associated antigen (TAA) [2]; cellular immunotherapies including dendritic cell (DC) vaccines [3]; and adoptive T-cell therapy such as tumor-infiltrating lymphocyte (TIL), cytotoxic T lymphocyte (CTL), transgenic T-cell receptors, and chimeric antigen receptors [4].