CD11c，also known as Integrin，alpha X (complement component 3 receptor 4 subunit) (ITGAX)，is a type I transmembrane protein found at high levels on most human dendritic cells，but also on monocytes，macrophages，neutrophils，and some B cells that induces cellular activation and helps trigger neutrophil respiratory burst; expressed in hairy cell leukemias，acute non-lymphocytic leukemias，and some B-cell chronic lymphocytic leukemias.
