Apoptosis-Induced Proliferation (AiP)

Apoptosis-induced proliferation (AiP) describes how the apoptotic death of large numbers of differentiated cells can mobilize nearby stem or progenitor cells into rapid compensatory proliferation, in order to replace the tissue that was lost. While this is a normal homeostatic repair response, the rapid DNA replication it demands carries a risk of acquiring oncogenic mutations. This makes AiP a notable exception to the general rule that blocking apoptosis promotes cancer: in some contexts (such as certain thymic lymphoma and intestinal cancer mouse models), preventing apoptosis of differentiated cells instead prevents tumor formation, because it removes the trigger for this compensatory, mutation-prone proliferation.