Human CD10, also known as common acute lymphoblastic leukemia (CALLA), has been shown to react with TdT+ lymphoblastic leukemia, follicular germinal cell lymphoma, Burkitt’s lymphoma, and chronic myelocytic leukemia. CD10 also marks normal early lymphoid progenitor cells, immature B-cells in adult bone marrow, and germinal cells in normal tonsil and normal lymphoid tissue. It is also expressed in some non-lymphoid tissues such as fibroblasts, breast myoepithelium, and brush border of kidney. Recently, CD10 has been used in a panel for mantle cell lymphoma with cyclin D1(+), CD43 (+), CD5 (+), IgM (+), CD23 (-) and CD10 (-).