CD11b and CD11c are integral components of the integrin family, which are heterodimeric transmembrane glycoproteins involved in cell adhesion and immune responses. CD11b, also known as integrin alpha M (ITGAM) or Mac-1, pairs with CD18 to form complement receptor 3 (CR3), playing a crucial role in mediating the uptake of complement-coated particles and pathogens. It is expressed on various immune cells, including macrophages, monocytes, granulocytes, and NK cells. Similarly, CD11c, also called integrin alpha X (ITGAX), forms complement receptor 4 (CR4) with CD18 and is involved in similar adhesive interactions and phagocytosis. Both CD11b and CD11c are commonly used as markers for immune cells, with CD11b/c antibodies often employed in research to identify microglia in the brain and other immune cells.