Apoptosis (Programmed Cell death) is one of the essential processes. Balance between cell division and cell death is of utmost importance for the development and maintenance of multi-cellular organism. Disorders of either process have pathologic consequences and can lead to disturbed embryogenesis, neuro-degerative diseases, or the development of cancers. This book reviews the apoptotic as well as anti-apoptotic molecules along with molecular pathways, which may alter in many diseases. The elucidations of the molecular mechanisms of apoptosis and their correlation with a vast array of human diseases have generated optimism for implementation of this knowledge for treatment purposes.