MMP-2 and MMP-9 concentrations were 1.02 and 1.03 times greater, respectively, for every 1-unit increase in log-transformed water arsenic (μg/L), and were 1.03 and 1.06 times greater, respectively, for 1-unit increase in log-transformed hair arsenic concentration (μg/g) after adjusting for age, sex, BMI, smoking and hypertension. The gene discussed is MMP9; the disease is Hypertension.