TLR7 and lung cancer: In other lines of research, authors such as Fabbri et al. defined in lung cancer cell lines the roles of miR-21 and miR-29a in the activation of toll-like receptor-7 (TLR7) and TLR8, causing the release of interleukin 6 (IL-6) or tumor necrosis factor alpha (TNFα), which are proinflammatory mediators and favor tumor proliferation [112].