Genetic models of abnormal apoptosis in lymphocytes

Apoptosis is a critical mechanism for regulating cell. numbers during devel opment, normal responses to hormones and other stimuli, and immune and infl ammatory reactions. Recent advances in defining the biochemical mechanisms of cell death, and the development of animal models with isolated defects i n cell death pathways, have led to an increasing appreciation of the pathop hysiologic importance of lymphocyte apoptosis. In this article, we review o ur current understanding of the pathways and roles of apoptosis in lymphocy tes, with an emphasis on transgenic and knockout models. We also summarize the relevance of these animal models to human diseases.