IL9 and irritable bowel syndrome: Taken together, it is clear that the intestinal DCs may promote the spleen CD4+, CD8+ T cell activation to produce more IL-4 and IL-9, resulting in visceral hypersensitivity in IBS, while PDIA3 knockdown can block the process and reduce the sensitivity by reducing the number of intestinal DCs and DC-induced T cell proliferation in these processes.