RORC and graft versus host disease: The absence of RORγt in T cells only had little impact and RORγt was dispensable to induce GVHD development in two independent studies (157, 158), while one study reported an attenuated effect on GVHD if both isoforms, RORγ and RORγt were absent in CD4 transplanted T cells due to KO of the entire Rorc locus (159).