Li et al. demonstrated that P. sanguineus polysaccharide (PPS) can delay the pathological changes of inflammatory bowel disease by upregulating the expression of ZO-1 and E-cadherin, proliferating cell nuclear antigen (PCNA), and reducing the proportion of Th cells to inhibit the helper Th cell-mediated immune response. This evidence concerns the gene PCNA and inflammatory bowel disease.