CD80 and rheumatoid arthritis: Of note, CTLA4-Ig 100 μg/mL downregulated the gene expression of TLR4, CD86, and significantly the one of CD80 after 3 h of treatment compared to unstimulated RA-MDMs (CD80: p < 0.05), whereas the high tested concentration of CTLA4-Ig downregulated the gene expression of all M1 markers, but not in a statistically significant manner (p = 0.06 for all M1 markers) (Fig. 3A).