Moreover, CD40 activation was shown to promote primary MCL cell proliferation, which is further enhanced by IL-4 or IL-10 co-stimulation.[6–8] Recent findings also demonstrated that IL-6 plays a critical role in promoting MCL cell growth, survival and drug resistance.[9] Identification of microenvironmental factors critical for MCL may be relevant not only to improve our knowledge on MCL pathogenesis, but it may also favor the exploitation of new therapeutic targets. The gene discussed is CD40; the disease is mantle cell lymphoma.