CD4 and graft versus host disease: Even though, we initially (day7) observed significant increases in proinflammatory cytokines, including TNF-a and IFN-g from CD4 T cells from TCF-1 cKO mice, this upregulation of TNF-a and IFN-g fails to recruit other inflammatory cells, such as macrophages to the site of inflammation to induce GvHD.