Autophagy

Autophagy is a highly conserved eukaryotic cellular recycling process. Through the degradation of cytoplasmic organelles, proteins, and macromolecules, and the recycling of the breakdown products, autophagy plays important roles in cell survival and maintenance. Accordingly, dysfunction of this process contributes to the pathologies of many human diseases. Different selective forms of autophagy have been identified and characterized, leading to the specific degradation of organelles or pathogens. 
Autophagy consists of several sequential steps--sequestration, transport to lysosomes, degradation, and utilization of degradation products. Autophagy signal transduction are mainly regulated by autophagy-related genes/proteins, Atgs.  Plenty of drugs and natural products are involved in autophagy modulation, either inducing or inhibiting autophagy, through multiple signaling pathways. Small molecules that can regulate autophagy seem to have great potential to modulate the clinical course of neurodegenerative diseases or promote chemotherapeutic response in tumor models.