Shown are schematic illustrations of different membrane trafficking pathways that involve autophagy (ATG) proteins (green ovals). See text for explanations of each pathway and a discussion of their physiological functions. See Table 1 for examples of genetic mutations that impair autophagy-related pathways which are associated with human disease. The major type of autophagy, macroautophagy, is labeled as “classical degradative autophagy” to distinguish it from other trafficking pathways that utilize overlapping ATG proteins. Due to space limitations, not all ATG proteins, proteins involved in vesicle fusion, or secretary cargo are depicted. PM, plasma membrane. LC3-II (green circle) is the phosphatidyl-ethanolamine-conjugated form of the autophagy protein, LC3.