The risk of hypertension was increased among subjects who had the habit of tobacco use (either smoking/chewing or both) carrying eNOS T-786C CC genotype (OR 9.00: 95% CI 1.14–71.04) in comparison with the subjects who had the habit of tobacco use (either smoking/chewing or both) carrying eNOS T-786C TC genotype (OR 4.51: 95% CI 2.69–7.56) and eNOS T-786C TT genotype (OR 5.84: 95% CI 3.79−8.98) (Table 5). The gene discussed is NOS3; the disease is Hypertension.