IRAK1 and rheumatoid arthritis: From our previous findings, we demonstrated that IL-18 induces VCAM-1 expression through Src kinase, PI3-kinase/Akt, and ERK1⁄2 signaling pathways [31], and outlined the participation of the IRAK/NF-κB pathway in RA synovial fibroblast VCAM-1 expression.