18 whereas immunostimulatory functions were suggested by the capacity of TGF-?? to induce cytokine expression in T cells and to promote effector expansion by inhibition of apoptosis.19-21 Moreover, the influence of TGF-?? on the development and function of other cells of the immune system, such as B cells, macrophages, and dendritic cells, has been reported.10 Striking evidence for the importance