Cluster of differentiation 11b (CD11b), also known as integrin subunit α M (ITGAM), is encoded by the gene mapped to human chromosome 16p11.2. It belongs to the integrin α chain family. CD11b is expressed by a variety of myeloid cell types, such as dendritic cells, macrophages, monocytes and neutrophils.
Cluster of differentiation 11b (CD11b) acts as a receptor for complement component C3 degradation product, iC3b. CD11b interacts with β2 chain (ITGB2) to form a leukocyte integrin (MAC-1 or complement receptor 3 (CR3)), which in turn plays a crucial role in adherence of neutrophils and monocytes to stimulated endothelium. Mutation in the gene increases the risk of susceptibility to systemic lupus erythematosus (SLE) and acute inflammatory demyelinating polyradiculoneuropathy (AIDP).
