IL1R1 and rheumatoid arthritis: All of these data suggest that IRAK-4 may be a suitable target for inflammatory diseases involving multiple receptors including IL-1R (rheumatoid arthritis (RA) and osteoarthritis (OA) [35]), IL-18R (inflammatory bowel disease (IBD) [36, 37]), TLR2, 4 (RA [38]), and TLR7, 9 (SLE [26, 29]).