The total number of cells in every multicellular organism is fundamentally fixed to a specific range. A type of programmed cell death happens in such organisms to effectively control the number of cells. This programmed cell death is called apoptosis. Characteristic cell changes and eventually death happens in cells due to certain biochemical events. It is a carefully controlled, energy-dependent process. An average adult human loses between 50 and 70 billion cells each day due to apoptosis, and an average human child loses about 20 to 30 billion cells. Apoptosis can be pathogenic when the death of healthy neurons leads to neurodegenerative diseases such as Parkinson's and Alzheimer's disease. This book contains some path-breaking studies in the field of apoptotic cell biology. It outlines the processes and mechanisms of apoptotic cells in detail. Researchers and students in this field will be greatly assisted by this book.