Mechanisms leading to induction of apoptosis by TNF family receptors involve intracellular activation of cysteinyl-aspartate-specific proteases (caspases). Caspase activation requires engagement of adaptor proteins. It is plausible, that caspase activation is sufficient for cell death in course of receptor-dependent induction of apoptosis. However, there are some data that programmed cell death involves also generation of ceramides, arachidonic acid metabolism, or MAP kinase (SAPK/JNK) activation. On the other hand, TNF receptor family triggers some protective, anti-apoptotic mechanisms, i.e. protein kinase C (PKC) and NF-kappa B. The outcome of induction of apoptosis by TNF receptor family depends on the cell type, its physiological condition and influence of environmental factors.