In order to determine the function of C/EBPβ as the target gene of miR-191 in RA-FLS, siRNAs targeting C/EBPβ (si-C/EBPβ-1 and si-C/EBPβ-2) were applied to knockdown the expression of C/EBPβ. Here, CEBPB is linked to rheumatoid arthritis.