GSTM1 and anemia (phenotype): Up to now, the only universally accepted definition of anemia in adults is that proposed by the WHO (Hb <13 g/dL in men and <12 g/dL in women), which dates back to 50 years ago.2 This definition has been criticized for a number of reasons, including the small number of subjects in the original dataset and inadequate/outdated methodology.3 Moreover, the reference population did not include subjects aged >65 years, making highly questionable the extension of such criteria to the elderly.