The absence of TCL1A staining seems a useful feature in defining SMZL: while in fact only 7/31 (22 %) of cases of SMZL showed positive staining for TCL1A, among cases of lymphomas that might mimic SMZL, 8/13 (61 %) of NMZL showed a mosaic-like, heterogeneously positive staining, while all nodal B-CLL/SLL (29/29) and 27/30 (90 %) nodal MCL showed strong and diffuse positivity for TCL1A (the remaining three MCL cases showed a weak or heterogeneous staining). The gene discussed is TCL1A; the disease is lymphoma.