The process of apoptosis is used to eliminate unwanted cells from a wi
de variety of organisms. Various ext extracellular signals, often conv
erging in common intracellular pathways, can induce apoptosis in a cel
l-type-specific fashion. Recent work from several laboratories has dem
onstrated that Rel/NF-kappa B transcription factors regulate apoptosis
in many cell types. In most cells, Rel/NF-kappa B transcription, fact
ors appear to mediate survival signals that protect cells from apoptos
is; however, under some circumstances, activation of these factors may
also promote apoptosis. (C) 1997 Academic Press Ltd.