To determine whether the TCF1+ subset is generated among alloreactive CD8+ T cells during the development of acute GvHD, we transplanted total splenocytes and bone marrow cells isolated from Balb/c (H2d) mice into lethally irradiated C57bl/6 (B6) recipient mice (H2b) to induce GvHD (Fig. 1A–C). Here, TCF7 is linked to graft versus host disease.