Pizzi M, et al. - Investigators examined the data to analyze the cortactin expression in non-Hodgkin B-cell lymphomas (B-NHLs) and also to evaluate its significance in the differential diagnosis of the disease. They characterized cortactin expression with immunohistochemistry among 131 B-NHLs candidates including B-cell chronic lymphocytic leukemia (CLL), mantle cell lymphoma (MCL), follicular lymphoma (FL), marginal zone lymphoma (MZL), hairy cell leukemia (HCL), splenic diffuse red pulp small B-cell lymphomas (SDRPBL), and diffuse large B-cell lymphoma (DLBCL) cases. They found no association of cortactin positivity with LEF1 and CD200 expression in CLL. They strongly predicted CLL diagnosis with combined positivity for ≥2 markers. They concluded that cortactin was chiefly expressed in subsets of CLL and DLBCL and in HCL. Overall, they exhibited cortactin, a novel marker for the differential diagnosis between CLL and MCL.