CDKN2A and cancer: Brain tissues of irradiated cancer patients show an upregulation of p16Ink4a-positive astrocytes compared to age-matched controls and untreated cancer patients. Irradiated astrocytes in vitro downregulate glutamate transporters and produce IL-6. In human astrocytes, Δ133p53 prevents radiation-induced senescence and ameliorates astrocyte-mediated neuroinflammation and neurotoxicity (Turnquist et al., 2019; Limbad et al., 2020).