IL2 and neoplasm: IL-2 is thought to drive anti-tumor immunity by enhancing the proliferation, survival, and effector function of lymphocytes that express the heterodimeric IL-2/IL-15 receptor (IL-2/15Rβ/common γ, CD122/CD132, Rβγ) (Waldmann et al., 1998; Waldmann, 2006), such as NK cells, activated T cells, and resting memory CD8+ T cells (Dubois et al., 2002).