SYT9 and periodontitis: From the top 10 differentially methylated genes in this GO term, STRING [20] indicated an interaction of 4 genes, SNAP23 (Synaptosome Associated Protein 23), SYT9 (Synaptotagmin 9), STX1B (Syntaxin 1B), and SYT2 (Synaptotagmin 2) with the periodontitis-associated genes VAMP3 [21, 22] and VAMP8 (Vesicle Associated Membrane Protein 8; Additional file 6) [23].