TGFB1 and rheumatoid arthritis: Similar to immunogenic DCs, tolDCs may be defined by integration of all the signals they transmit to T cells, including maturation marker expression, as well as the presence of, in this case, anti-inflammatory-related tolerizing signals consisting of surface molecule expression (PD-L1, ILT3/4, ICOSL, CTLA-4), tolerogenic cytokine profiles (IL-10, TGFβ) and the presence of other tolerance-inducing metabolites (IDO, RA) (14, 22).