Apoptosis in disease

Background: Apoptosis, the death of a single cell according to an exactly defined intracellular program, is a key principle allowing embryonic development and later on tissue homeostasis in metazoans. Molecular Base: The molecular base is an evolutionary highly conserved intracellular signaling cascade, which is preserved from nematodes to mammals. Initiation of the program finally leads to the activation of caspases, a set of cysteinyl-specific proteases, which indicates the beginning of the end of a cell life. During evolutionary development, the role of central effectors did not change, but an enormous sophistication of necessary control mechanisms evolved. In recent years it became clear that subtle changes in the fine-tuned balance of life and death of single cells are the underlying cause of many diseases. Aims and Conclusion: Our review focuses on clinical aspects of apoptosis. In the first part the major proteins forming the deadly intracellular cascade will be discussed, while the second part relates to diseases which are characterized by a dysfunction of the apoptotic program.