Antigen distribution: CD10 is expressed on early B and T lymphoid precursors, B blasts, some granulocytes and bone marrow stromal cells. CD10 is also expressed on various epithelia, some smooth muscle and myoepithelial cells, brain and fibroblasts. CALLA is also present on other types of B and T cell tumors and on normal peripheral blood granulocytes. Cellular Expression: Common acute lymphoblastic leukemia antigen.