CCND1 and graft versus host disease: After administering two doses of IFNγ in vivo 24 h apart, assessment of gene expression 24 h after the last dose indicated ISC upregulation of both Myc and Ccnd1 (Fig. 6f), consistent with findings from mice with GVHD (Fig. 4) and findings from IFNγ treatment ex vivo (Fig. 5).