Mutations in T‐cell surface glycoprotein CD3 gamma chain (CD3γ) abrogate the integrity of the complex and result in autoimmunity, accompanied by IBD, due to T‐cell phenotypic and functional defects, especially in Treg.140 Therefore, it is postulated that the pathomechanism of IBD in CD3G deficiency stems from the dysregulation due to reduced Treg function.140. Here, CD3G is linked to inflammatory bowel disease.