PTGS2 and hepatocellular carcinoma: We then used siRNA to block TLR4/9 activity in HCC cells and found that NETs were insufficient to induce phosphorylation of NF-κB pathway (P65) and COX2 expression in HepG2si-TLR4/9 and MHCC97Hsi-TLR4/9 cells (Fig. 5c).