Moreover, we further found that TLR4 knockdown cells grew slower than parental cells in vivo, whereas TLR4 knockdown cells grew similar to parental, or scramble shRNA-infected cells in 2D culture, indicating that tumor microenvironmental factors secreted by host immune cells are necessary to induce TLR4-mediated tumor growth [30]. This evidence concerns the gene TLR4 and neoplasm.