Dominant negative dnIKK2 was also found to inhibit cytokine production from both TNF-α and IL-1β stimulated macrophages and RASF fibroblasts, as well as IL-6 and IL-8 production in LPS stimulated RASF cells, supporting the idea of an important role for IKK2 in RA. Here, IL1B is linked to rheumatoid arthritis.