PTGS2 and rheumatoid arthritis: We were able to confirm some known RA related genes in the present study, such as Stat3, Bst1 (bone marrow stromal cell antigen 1), Ptgs2 (prostaglandin G/H synthase 2), S100a9 (S100 calcium binding protein A9) and Ets1 (Ets avian erythroblastosis virus E2 oncogene homolog 1), in addition to chondroitin sulfate proteoglycan 2, Galectin3 and Socs3 (suppressor of cytokine signaling 3).