ITGAD encodes integrin alpha-D, a β2-integrin subunit that functions as a leukocyte adhesion receptor 1. As part of the CD11d/CD18 complex, ITGAD mediates cell-cell adhesion through interactions with endothelial ligands ICAM3 and VCAM1, contributing to leukocyte extravasation and mesenchymal migration during immune responses 1. ITGAD plays roles in clearing blood-borne pathogens and senescent erythrocytes through phagocytosis and may participate in atherosclerotic plaque clearance [UniProt annotation supported by 24]. Clinically, ITGAD dysregulation is associated with recurrent implantation failure (RIF) in IVF patients, where downregulation of ITGAD expression impairs embryo-endometrial attachment 34. The lncRNA LINC02190 regulates ITGAD promoter activity, and its upregulation in RIF endometrium decreases ITGAD expression and reduces trophoblast-endometrial cell adhesion 4. ITGAD has also emerged as a candidate gene in fibromyalgia pathogenesis, with altered expression correlating to immune cell infiltration patterns 5. Additionally, a genetic variant in ITGAD (rs2454908) shows association with alcohol craving among alcohol-dependent individuals 6, suggesting ITGAD involvement in addiction-related neurobiological processes. These diverse disease associations highlight ITGAD's importance beyond its canonical adhesion functions.