TLR4 and rheumatoid arthritis: From the KEGG differential gene pathway analysis, TLR4 enrichment was also involved in a variety of signaling pathways, such as the PI3K-Akt pathway, influenza virus A pathway, hepatitis B signaling pathway, phagocytic signaling pathway, Toll-like receptor signaling pathway, Salmonella infection signaling pathway, cancer proteoglycan, hypoxia inducible factor signaling pathway, inflammatory bowel disease signaling pathway, rheumatoid arthritis signaling pathway, ER stress, nuclear factor (NF)-κB signaling pathway, and many other important signaling pathways related to tumors and inflammation.