The TGF-β family comprises many cytokines involved in the control of cell fate 1. Some of these have been shown to control cell death. For instance, at least one of the members of the BMP subfamily of the TGF-β family is required in interdigital death, a classical model of developmentally programmed cell death 2. Another TGF-β family member, TGF-β1, entertains a complicated relationship with cell death, of lymphocytes in particular. When added extracellularly, it has been reported to induce death of B lymphocytes 3,4 and to prevent T lymphocyte death 5,6,7.
A new, and at times somewhat heretical twist, is now reported 8. In mice homozygous for a TGF-β1 null mutation 9,10, thus not expressing TGF-β1, W.J. Chen et al. 8 found that apparently spontaneous apoptosis...
