Moreover, cytokines secreted by senescent cells such as interleukin-6 (IL-6) and C-X-C pattern chemokine ligand 1 (CXCL1) are also shown to promote tumor development by stimulating endothelial cell proliferation, promoting angiogenesis, facilitating tumor cell invasion, or inducing cancer stem cell formation (Liu et al., 2018). This evidence concerns the gene IL6 and cancer.