Autophagy is a cytoplasmic process where worn-out organelles and intracellular structures are enveloped by a membrane and degraded in the lysosome. This evolutionarily-conserved process is central to a variety of essential cellular processes, from regulation of the nutritional state of the cell to immune response mechanisms against viruses. Due to the important and ubiquitous nature of autophagy, alteration in the autophagic machinery has been linked to several diseases including cardiovascular diseases, neurodegenerative diseases, autoimmune diseases and several forms of cancer. This thesis explores autophagy and its physiological and pathological roles in humans with special emphasis on cancer development and therapy.