Comments by David Baltimore, a professor of biology and president of the California Institute of Technology
Apoptosis. Programmed cell death. Several proteins carry a signal that commands cells to commit suicide for the greater good of the organism.
But if these portable time bombs are circulating around the bloodstream, what protects all of the normally functioning cells from destruction? One explanation is that protective mechanisms prevent cells from following the apoptosis order. In fact, this study suggests that TNF-alpha --a powerful cell death signal--sends two simultaneous signals: one an instruction to commit suicide, and the other activating a cellular protein complex--called NF-kappa B--that prevents cellular suicide.
NF-kappa B--made up of two independent proteins called p50 and p65--was first uncovered...