TGFB1 and colitis: At 1 day and 3 days after intraperitoneal injection of hUC-MSCs, the levels of TGF-β1 levels in the MLNs (Fig. 4E), colon (Fig. 4F) and spleen (Fig. 4G) of colitis mice with hUC-MSCs treatment were all significantly increased compared to those in colitis mice.