In contrast, SAP2 (49/66), SAP3 (38/66), SAP4 (32/66), SAP5 (41/66), SAP6 (51/66), SAP7 (46/66), and SAP8 (44/66) were predominantly expressed in strains from moderate periodontitis, with lower frequencies in strains from gingivitis and chronic periodontitis. Here, GM2A is linked to periodontitis.