TLR9 and neoplasm: Rusanen et al. (2024) found that OSCC tissues exhibited reduced expression of TLR1–5, TLR7, and TLR8 in the basement membrane and endothelium, while infiltrative tumour zones showed increased TLR1, TLR2, TLR4, TLR8, and TLR9 expression, suggesting localised immune activation.