PTX3 and inflammatory bowel disease: However, in the mouse model of IBD, knocking-down PTX3 in CD317+ MSCs reduced the serum level of TSG6 and therapeutic effects (Fig. 7C), while overexpressing PTX3 in CD317− MSCs increased the serum level of TSG6 and therapeutic effects (Fig. 7D), indicating that the PTX3 might regulate the protein stability of TSG6.