CD8A and graft versus host disease: Another study, in a non-human primate GvHD model, utilized intravascular staining combined with scRNA-seq to demonstrate that donor-derived CD8 T cells infiltrating into the GI tract were highly activated and cytotoxic and that levels of CD8 T cell infiltration into the GI tract were positively correlated with severity of GvHD,9 consistent with the current study.