Independent of the underlying causes, recent trials [73] signal a higher frequency of fatal and non-fatal cardiac events in individuals with normal as compared to reduced hemoglobin and hematocrit concentrations; this casts doubt on whether reducing prevalence of anemia should be a primary goal of treatment in ESRD, although it is prudent to support Hb concentrations at a certain minimal level, even within the anemic range. The gene discussed is GSTM1; the disease is anemia (phenotype).