KYNU and rheumatoid arthritis: Additionally, MMP7 and B-cell lymphoma 2-related protein A1 (BCL2A1) were up-regulated across periodontitis, CVD, and UC, while the genes kynureninase (KYNU), regulator of G-protein signaling 1 (RGS1) and serpin peptidase inhibitor, clade A (SERPINA1) were up-regulated across periodontitis, CVD, and RA (Fig. 5a).