Erlotinib decreased the phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 through the PI3K–Akt signaling pathway after lipopolysaccharide treatment and downregulated the expression of TLR4 on macrophages, thereby regulating the microenvironment or systemic anti-tumor immunity (Xue, et al., 2021). This evidence concerns the gene TLR4 and neoplasm.