SOD2 and cancer: Beyond cancer, the frequent pro-inflammatory nature of the SASP is believed to be responsible for the toxic effects that accumulating senescent cells exert in aged organisms [81], which links to the fourth aspect of context, ageing. This was elegantly shown by Velarde et al. applying in young and old mice the model of mitochondrial dysfunction based on superoxide dismutase 2 (Sod2) deficiency, which leads to cellular senescence.