TLR9 and nasopharyngeal carcinoma: As expected, proinflammatory receptors such as IL1RL1 (IL-33), IL1R1, IL17RA, IL18RAP, IL20RB, IL4R, IL6R, and Toll-like receptor families (TLR2, TLR3, TLR4, TLR6, TLR8, and TLR9) were also downregulated by NPC-CM.