Integrin beta 2
In molecular biology, CD18 (Integrin beta chain-2) is an integrin beta chain protein that is encoded by the ITGB2 gene in humans. Upon binding with one of a number of alpha chains, CD18 is capable of forming multiple heterodimers, which play significant roles in cellular adhesion and cell surface signaling, as well as important roles in immune responses. CD18 also exists in soluble, ligand binding forms. Genetically-inherited deficiencies in the ITGB2 gene can lead to reduced surface expression of the CD18 protein, leading to the immunodeficiency leukocyte adhesion deficiency.