The contradictory role of autophagy i.e. cell survival versus cell death; draws the focus on the importance of keeping in mind this double-edged nature in future developments of the currently promising autophagy-modulating therapies. This book highlights some of the demanding research topics related to autophagy and also analyzes the recent developments in its molecular mechanisms. The emphasis is on the role this basic cell defense mechanism plays in studying various diseases which include autophagy in infectious diseases, in neurodegenerative diseases, and cell death.