Also, using MR, we show that genetic instruments for potential confounders such as HbA1c, diabetes, BMI and waist-to-hip ratio do not affect DNMT3A-R882-CH prevalence, providing further independent support for a causal relationship between metformin and reduced DNMT3A-R882-CH. The gene discussed is DNMT3A; the disease is cyclic hematopoiesis.