Immunohistochemically, the low and intermediate grade B-cell lymphomas show the following immunophenotypes: follicular lymphoma, CD5-, CD10 +, CD23 -, CD43 -, cyclin D1 -; MALT lymphoma, CD5-, CD10-, CD23-, CD43+/-, cyclin D1 -; mantle cell lymphoma, CD5+, CD10-, CD23-, CD43 +/-, cyclin D1 + [2]. This evidence concerns the gene CD5 and mantle cell lymphoma.