Interestingly, senescent cells are not entirely benign. They secrete a variety of pro-inflammatory cytokines, growth factors, and proteases known as the senescence-associated secretory phenotype (SASP). While SASP can reinforce the senescence of neighboring cells and recruit immune cells to clear senescent cells, it can also create a pro-tumorigenic microenvironment. Chronic inflammation and the secretion of growth factors can paradoxically promote the growth of nearby pre-cancerous or cancerous cells.
