IL2 and viral infectious disease: In particular, interleukin-2 (IL-2), a member of the common cytokine receptor gamma-chain (γc) family of cytokines, has a key role to maintain antigen-specific effector and memory CD8+ T cells during viral infections (Bachmann et al., 2007; D'Souza and Lefrançois, 2003; Kalia et al., 2010; Malek and Castro, 2010; Williams et al., 2006).