Factors linked to the induction of SIPS vary widely, from DNA damage – for example, radiation (bovine aortic endothelial cells [45]), UV light (human fibroblasts [46] and human melanocytes [47]), chemical treatment (nasopharyngeal carcinoma cells [48] and human fibroblasts [49,50]), and oxidative stress (human fibroblasts [20,22,24] and human articular chondrocytes [19]) – to oncogenic protein overexpression (for example, ras in human fibroblasts [51]) and exposure to inflammatory cytokines such as IL-1 and tumour necrosis factor-α (human chondrocytes and fibroblasts [19,21,23]). Here, IL1B is linked to nasopharyngeal carcinoma.