Apoptosis is a fundamental process to regulate homeostasis of all tissues and to eliminate unwanted cells specifically in the immune system. Various parts of apoptosis signaling pathways have been characterized. The group of Marcus Peter has been studying apoptosis pathways initiated by members of the death receptor family such as CD95 (Fas/APO-1) and many of its main signaling components. However, it has become clear in recent years that death receptors such as CD95 and all of its signaling components have nonapoptotic activities that in the context of cancer can cause tumor promotion and progression. The Peter Lab investigates the activities of death receptors and their signaling components in apoptosis and the relevance of their nonapoptotic activities in cancer development. In addition, the group is interested in the role of microRNAs in various aspects of carcinogenesis. Most recently, the Peter Lab started to unravel the reason why certain RNAs are toxic to cancer cells through RNA interference.