EGLN1 and Splenomegaly: We demonstrate herein that selective ablation of PHD2 expression in Treg (PHD2ΔTreg mice) leads to a spontaneous systemic inflammatory syndrome, as evidenced by weight loss, development of a rectal prolapse, splenomegaly, shortening of the colon, and elevated expression of IFN-γ in the mesenteric lymph nodes, intestine, and spleen.