Ribosomal S6 kinase 2 (RSK2) is an important kinase that modulates the transactivation activities of AP-1 and NF-κB, which regulate Cox-2 gene expression in cells where growth factors and/or environmental stresses are present18–20, indicating the potential role of RSK2 in inflammatory diseases, such as RA. Here, PTGS2 is linked to rheumatoid arthritis.