Our study found that increased levels of lipid mediators such as sphingosine 1-phosphate (S1P) and 12-HETE and lysophospholipids such as LPE (18:1), LPE (18:2), lysophosphatidylcholine (LPC 18:1), LPC (18:4) and lysophosphatidylserine (LPS 18:0) in RA patients were positively correlated with CRP levels (Fig. 3), supporting their roles in inflammation. Here, CRP is linked to rheumatoid arthritis.