ABCA4 and systemic lupus erythematosus: The differential metabolites of HC vs. SLE-d were mainly involved in alpha-linolenic acid metabolism (stearidonic acid, alpha-linolenic acid, jasmonic acid), biosynthesis of unsaturated fatty acids (adrenic acid, alpha-linolenic acid), ATP-binding cassette transporters (l-proline and colistin), and bile secretion (fexofenadine, cholic acid).