Change of view in functions of senescent cells with the discovery of SASP . After its discovery, cellular senescence was viewed as a process stably blocking cell proliferation and thus thought to inhibit proliferation-dependent processes, such as cancer, tissue renewal, or reprogramming (highlighted in black rectangle). After the discovery of the SASP in 2008, the potential effects of senescent cells were no longer limited to cell autonomous effects and to cell proliferation-associated processes. Some examples of the functions of the SASP are mentioned, and they include reinforcement of the senescence phenotype, induction of paracrine senescence (red arrows), and regulation of other processes, highlighted in the red rectangle.