In a hypothetical patient with WFNS grade 4 SAH (Glasgow Coma Scale (GCS) score of 9, without a focal neurological deficit) and the development of anemia on the third day in the hospital, the mean Hb concentration at which clinicians would choose to administer RBCs was 8.19 g/dL (95% confidence interval (95% CI), 8.07 to 8.30; medians and interquartile ranges (IQRs) are presented in Figure 1). The gene discussed is GSTM1; the disease is anemia.