 CD40 is also expressed on B cell precursors in the bone marrow, and there is some evidence that CD40-CD154 interactions may play a role in the control of B cell haematopoiesis.CD40 (protein) has been shown to interact with TRAF2, TRAF3, TRAF6, TRAF5 and TTRAP.CD40 molecule is a potential target for cancer immunotherapy.