TLR5 and mantle cell lymphoma: [51,55] Moreover, proteins derived from Borrelia flagella are able to both entail an upregulation of TLR5 expression in monocytes, [54] and reduce the expression of the same TLR in mucosal dendritic cells.[56] We need thus to further investigate the influence of the whole bacterium, and not only the derived TLR ligands, on MCL cells, to better understand whether Borrelia infection might constitute a microenvironmental factor potentially able to promote MCL cell growth through the potent stimulation exerted by activation of these TLRs, at least in a subset of MCL cases.