Figure 1. Schematic overview of the autophagic process. Various stimuli such as starvation, oxygen shortage, and ionizing radiation induce autophagy. Initially, a phagophore is formed and begins to encapsulate molecules that will degrade. Subsequent nucleation and elongation lead to the formation of the characteristic double-membraned autophagosome. After the formation of the autophagosome, lysosome approaches to fuse. The formation of an autophagolysosome accompanies fusion. After fusion, the degradation of the sequestered cytoplasmic cargo involves several acid hydrolases. These hydrolases are then recycled.