Recent studies have identified and begun to characterize the roles of regenerative cellular
plasticity in many organs. In Part I of our two-part Review, we discussed how cells reprogram
following injury to the stomach and pancreas. We introduced the concept of a conserved
cellular program, much like those governing division and death, which may allow mature
cells to become regenerative. This program, paligenosis, is likely necessary to help organs
repair the numerous injuries they face over the lifetime of an organism; however, we also …

For the last century or so, the mature, differentiated cells throughout the body have been
regarded as largely inert with respect to their regenerative potential, yet recent research
shows that they can become progenitor-like and re-enter the cell cycle. Indeed, we recently
proposed that mature cells can become regenerative via a conserved set of molecular
mechanisms ('paligenosis'), suggesting that a program for regeneration exists alongside
programs for death (apoptosis) and division (mitosis). In two Reviews describing how …