In vitro, FL stromal cells decrease tumor B cell apoptosis through a set of partially resolved mechanisms, including the production of hedgehog ligands (Hh), BAFF and TGF-β, over- expression of ABC-type multi-drug transporters, and activation of a c-MYC/HDAC6 loop in tumor cells (24, 73). Here, HDAC6 is linked to neoplasm.