TLRs have been shown to be overexpressed in different cancers, such as TLR7 and TLR8 in pancreatic cancer; TLR3, TLR4, TLR7, and TLR9 in esophageal cancer; TLR4, TLR5, and TLR7–9 in lung cancer; and TLR2–5 in ovarian cancer18,21. Here, TLR7 is linked to lung cancer.