The roles, mechanisms, and controversies of autophagy in mammalian biology

Autophagy is a universally conserved metabolic program of catabolism that plays important roles in energy homeostasis and impacts both normal physiology and multiple disease processes, including cancer. Autophagy has been documented as a pro-survival mechanism used to maintain viability under starvation conditions; however, conflicting findings have also implicated autophagy in the control of cell death. Adding to the controversy, central mediators of autophagy have been implicated in both pro-survival and pro-death processes. This report highlights recent insights into our understanding of how autophagy is regulated and newly discovered physiological roles for autophagy in normal biology and disease.