TNFRSF1B and rheumatoid arthritis: We previously reported that m1 Ig1&2-Fc shows additive efficacy with Fc-tagged p75 mTnfr2 (here called mEta) when the 2 biologics are coadministered together at suboptimal doses in the CIA model, a model of RA that is highly sensitive to TNFi (12, 18, 19).