Cell extrusion

Cell extrusion, discovered in 2001 by Jody Rosenblatt, is a process conserved in epithelial from humans to sea sponge to seamlessly remove unwanted or dying cells while maintaining the integrity of the epithelial barrier. If cells were to die without extrusion, gaps would be created, compromising the epithelia's function. While cell targeted to die by apoptotic stimuli extrude to prevent gaps from forming, most cells die as a result of extruding live cells. To maintain epithelial cell number homeostasis, live cells extrude when they become too crowded.