However, it is not straightforward to draw such conclusion yet because these studies have not only different sample sizes, but also different instruments (ALDH2 genotype being a stronger instrument than ADH1B genotype), different ethnic backgrounds (Korean and Chinese compared with European) and different methods were used to define cardiovascular disease (self- report and self- report compared with combination of self- report, medical records, clinical/lab measures, death certificate and ICD code). This evidence concerns the gene ALDH2 and cardiovascular disorder.