The lower numbers of terminally differentiated Th subsets and the expansion of intermediate CD4+ T cells in the MLN of steroid-treated IEC-Ceacam1–deficient recipients with GVHD were associated with lower TCR, IL-2/Stat5, IL-6/Stat3, and TLR signaling and higher activity in the glycine-serine/threonine and valine-leucine/isoleucine pathways. This evidence concerns the gene CD4 and graft versus host disease.