As reviewed elsewhere, IL-22 appears to contribute to host defense at peripheral sites (Zenewicz and Flavell, 2008; Ouyang et al., 2011; Rutz et al., 2014), while in the brain IL-22 can function as a cell survival factor as it protects glioblastoma cells from the apoptosis-inducing effects of serum starvation and Fas ligand exposure (Akil et al., 2015). Here, IL22 is linked to glioblastoma.