SERPINE1 and dental caries: Worldwide different ACE and PAI-1 SNP based case-control association studies have implicated ethnicity as an important disease susceptibility risk factor [12], not only for diabetes but also other diseases including myocardial infarction [11], schizophrenia [13], cardiovascular disease [14], dental caries [15], etc. ACE is a key regulator of RAS, which catalyzes the conversion of angiotensin I to angiotensin II.