To extend this finding, we aimed to test whether alcohol flushing could be used as an alternative phenotypic IV for alcohol intake (and be used as a valid proxy for the rs671 variant in the ALDH2 gene) by comparing the IV results when using alcohol flushing with the MR results (i.e., using the rs671 genotype) within the same population, which estimated the effect of alcohol intake on BP and hypertension (Fig. 1). This evidence concerns the gene ALDH2 and hypertensive disorder.