TAS2R38 and dental caries: Several previous studies have identified an association between several genes and dental caries [14], including genes related to enamel formation such as AMBN, AMELX, and ENAM [15]; taste receptor genes such as TAS2R38, TAS1R2 [16,17]; immune-related genes such as HLA [18]; and saliva genes such as MUC5B, PRH1 [19,20].