Multiple pathways to apoptosis.

Evidence from studies dealing with various aspects of the interdigitating network of proliferative signals supports the concept of multiple signalling pathways. Analogous to these, the concept of multiple pathways to apoptosis is introduced and discussed. Some of these pathways might not necessarily be under genetic control. They might be elicited by a perturbation at any point in the proliferative signalling network, for example by an imbalance in any of the substances involved directly or as second messengers. Diverse findings from recent reports on the induction of apoptosis by various means and in a variety of cell lines imply the presence of such multiple pathways, only one of which should accurately be described as genetic.