Our data demonstrating activation of caspase-1 (Figs. 1D–G, 5D, 6B, and 7D), morphological hallmarks consistent with inflammatory cell death (Figs. 5B, F and S6), GSDMD processing temporally associated with caspase-1 activation (Fig. 5D), and increased PI and Zombie dye uptake (Figs. 5C, S6E, and 6C–E) in mouse and human T cells in in vitro and in vivo models of GvHD suggest that these cells are pyroptotic, though genetic manipulations to inhibit caspase-1 would be necessary to confirm this. Here, CASP1 is linked to graft versus host disease.