The TNF cytokine family: one track in a road paved by many.

During the quarter of a century since TNF was isolated, much knowledge has been gained of the identity of other ligands besides TNF in the TNF cytokine family, and of the proximal signaling molecules that these ligands activate. The numerous laboratories contributing to this advance have approached TNF research from various points of view. The research pathway taken in my own laboratory, which is outlined in this article, has been driven by the desire to elucidate mechanisms that regulate cell death.