TLR7 and synovial sarcoma: Zheng et al. reported that the mRNA levels of TLR7 and TLR9 in peripheral blood mononuclear cells (PBMCs) were elevated in patients with SS compared to controls, and TLR7- and TLR9-positive cells were found in the epithelial islands, lymphocytes, and ductal epithelial cells of the parotid glands in patients with SS, whereas they were limited to ductal epithelial cells in controls [28].