Also, human sera contain preferentially serum antibodies directed against TarS-dependent β-O-GlcNAcylated WTA, but not against TarM-mediated α-O-GlcNAcylated WTA25, suggesting that tarM may be down-regulated or less immunogenic than β-O-GlcNAcylated WTA during infections. This evidence concerns the gene TARS1 and infection.