24 hours after co-transfection of miR-146b mimic and 3′UTR of NFKB1, MAP3K7 and TRAF6, the luciferase activity significantly decreased compared to the negative control in two immune cell lines and an HCC cell line (Fig. 7C,D), which indicated that miR-146b directly regulates NF-kB signaling.miR-146b was mainly expressed in the immune cells. This evidence concerns the gene TRAF6 and hepatocellular carcinoma.