Cell Death, Compensatory Proliferation, and Cell Competition.

Cell death, compensatory proliferation, and cell competition are fundamental interconnected processes that shape how tissues develop, maintain homeostasis, and regenerate. In this review, I highlight how cell death (apoptosis) not only eliminates excess and damaged cells but can also initiate compensatory proliferation, an adaptive response that occurs following cell loss. I examine cell competition, a quality-control mechanism that removes less fit loser cells in favor of healthier winner neighbors. Cell competition is intricately linked to cell death and compensatory proliferation. I present the history of these processes, discuss the most important examples, and reveal the key molecular mechanisms that underlie them. I incorporate findings from Caenorhabditis elegans, Drosophila melanogaster, vertebrates, and other models to underscore the conservation of the key molecular signaling events. I also discuss how misregulation of these processes can contribute to pathological conditions, including cancer.