PTGER4 and rheumatoid arthritis: +IL-1a [3], IL-1b [12], TNF [2], HMGB1, bradykinin, PGE2, EP2, EP4, TLR7, norepinephrine,* EDPs, LPS [4], poly(I:C), infection (C. albicans [2], C. glabrata, C. tropicalis, CHIKV, HIV), zymosan, nerve inflammation (monosodium urate), human disorder (vulvodynia [3], RA [3], OA, total knee arthroplasty, ligament injury, FM, frozen shoulder)