CD11b [MD131]

CD11b, also known as ITAM, Integrin alpha-M or MAC-1 alpha subunit or CR3 alpha chain belongs to the integrin alpha chain family; it is predominately presented in human myeloid cells, NK1 cells, monocytes, granulocytes and follicular dendritic cells. The alpha subunit of ITAM/beta-2 complex (CD11b/CD18, Mac-1), is a receptor for fibrinogen, factor X, and ICAM1. ITAM/beta-2 is implicated in adhesive interactions of monocytes, macrophages, and granulocytes. CD11b has been used as a common myeloid marker. CD11b is expressed in about 50% of acute myeloid leukemia (AML). In combination with CD117, CD11b is helpful in differentiating acute promyelocytic leukemia (CD11b negative) from recovering benign myeloid proliferation (CD11b positive, CD117 negative). In acute promyelocytic leukemia patients treated with all-trans retinoic acid or Arsenic trioxide (As2O3), CD11b is a marker for differentiating the induction of leukemia cells. CD11b is also expressed on microglia cells and involved in the development of neurodegenerative diseases.