Madcam1, also known as mucosal addressin cell adhesion molecule 1, is a crucial adhesion molecule. It plays a vital role in lymphocyte homing, especially in the gut-associated lymphoid tissue, by interacting with its receptor α4β7 integrin. This interaction is involved in regulating immunity and inflammation processes. The NKX-COUP-TFII morphogenetic code has been identified to direct its expression [6].

In various disease models, Madcam1 has shown significant effects. In cancer, post-antibiotics gut recolonization by Enterocloster species down-regulates ileum Madcam1, leading to the emigration of enterotropic α4β7+CD4+ regulatory T 17 cells into the tumor, indicating its role in cancer immunosurveillance [1]. In colitis, optogenetic activation of local colonic sympathetic innervations reduces endothelial MAdCAM-1 expression, attenuating experimental colitis and immune cell extravasation [2]. In acute liver failure, MAdCAM1 levels are induced and positively correlated with liver damage; activating the cholinergic anti-inflammatory pathway down-regulates MAdCAM1, alleviating liver injury [3]. In glaucoma, MAdCAM-1 is induced in retinal endothelial cells by elevated intraocular pressure, and its neutralization ameliorates retinal ganglion cell loss [4]. In Crohn's disease, treatment with anti-TNF-α reduces the number of MAdCAM-1-positive mucosal capillaries [5]. In checkpoint inhibitor colitis, endothelial cells upregulate MAdCAM-1, which may respond to vedolizumab [7].

In conclusion, Madcam1 is essential for lymphocyte homing and immune-related processes. Studies using gene-related models, such as those in cancer, colitis, liver failure, glaucoma, Crohn's disease, and checkpoint inhibitor colitis, have revealed its role in disease-associated inflammation, immune cell trafficking, and disease progression. Understanding Madcam1 can potentially provide new therapeutic targets for these diseases.