TLR4 and rheumatoid arthritis: Moreover, overexpression of miR-506 decreased TLR4 expression on both the mRNA and protein levels (Figure 5C,D), while an increased TLR4 expression was observed in RA synovial tissues (Figure 5E), and its expression correlated inversely with that of miR-506 in RA synovial tissues (Figure 5F).