Additionally, the chronic inflammation observed in AD may be related to increased levels of interleukin (IL)-4, IL-13, and IL-31, which can cause alterations in both the structures and expression levels of occludin-1, cingulin, and claudin-1 with the aim of re-establishing barrier function, although with limited efficacy [38,39,40]. The gene discussed is IL4; the disease is Alzheimer disease.