TLR9 and hepatocellular carcinoma: Despite the typical intracellular localization of TLR9 in endosomes, two additional sites of expression were described: (1) the cell surface of human and mouse neutrophils, intestinal epithelial cells (IEC), mouse colonic tissue, and hepatocellular carcinoma cells (35–37) and (2) a soluble form in bacterial pleural effusions and human embryonic kidney 293 cells (Figure 1A) (38, 39).