CX3CL1 and rheumatoid arthritis: For RA (Figure 3a), we found negative correlations between sphingomyelins (SM 42:1;O2 and SM 44:1;O2), phospholipids (PA 46:3, PG 43:2, PE 40:3), and the ether phospholipid (PE-O 42:5) with IL-12p70, CX3CL1, and TNFα.