TNFRSF1B and rheumatoid arthritis: •A therapeutic humanized mAb binding to both soluble TNF (sTNF) and transmembrane TNF (tmTNF)•Increases expression of tmTNF on monocytes from rheumatoid arthritis (RA) patients (in vitro assay)•Promotes the binding of tmTNF (expressed on monocytes) to TNFR2 (expressed by Tregs of RA patients), resulting in selective activation and proliferation of Tregs (in vitro assay)