CD43 is a transmembrane protein involved in immune function and T-cell activation. Anti-CD43 reactivity is seen in T lymphocytes, monocytes, and granulocytes. No reactivity has been observed in normal or reactive B-cells. Reportedly, anti-CD43 reactivity is seen in the majority of T-cell lymphomas and some low grade B-cell lymphomas. Therefore, anti-CD43 is a useful immunohistochemical marker for the identification of T-cell lymphomas and some low grade B-cell lymphomas.^1-2