,21,22,23,24,25 In contrast, CD37 expression in cancer has been demonstrated in B cell non-Hodgkin lymphoma (B-NHL),26 but it was recently observed that CD37 expression is not a hallmark of all B cell malignancies; some recent studies demonstrated that only 60% of follicular lymphoma (FL)27 and only 40% of diffuse large B cell lymphoma (DLBCL)28 tested positive. Here, CD37 is linked to follicular lymphoma.