MRC1 and rheumatoid arthritis: Treatment of RA sorted CD206+CD163+ macrophages with a CD40-TRAF6 signaling inhibitor resulted in decreased expression of TNFα, IL-1β, IL-6, and interferon-γ (IFN-γ) in two patients with a variable response observed for the third patient, indicative of patient heterogeneity (Fig. 3H).