GSTM1 and anemia (phenotype): Zakai et al. reported a median 3-year change in Hb levels of −0.4 (−0.9 to 0.1) g/dL (males: −0.5 [−1.1 to 0.1] g/dL, females: −0.5 [−1.1 to 0.1] g/dL) in 3,758 older healthy adults without anemia [6].