Table 2 lists the effects of activation of α7 nAChRs on IBD. Other nAChR subtypes including α4β2* have been reported to be expressed by a subset of intestinal and peritoneal macrophages that do not express α7 receptors and are not directly involved in the anti-inflammatory effects of the CAP but instead serve a phagocytotic function in the gut [114]. Here, CHRNA4 is linked to irritable bowel syndrome.