Six drug targets (LSS, ABAT, SQLE, FDFT1, CAT, CS) were common to RA and MS; five drug targets (NAMPT, EPHX2, COMT, HIBCH, GAA) were common to RA and PBC; and two drug targets (ADH5, FASN) were common to MS and PBC. This evidence concerns the gene CAT and rheumatoid arthritis.