GSTM1 and Neurodevelopmental delay: Lawler et al. demonstrated a similar Hb threshold for NDD-CKD patients Stage 3 to 5 in a study of 97,636 patients in the Veterans Administration Healthcare System; this analysis also showed that the use of ESAs and/or iron, at any hemoglobin level, was responsible for a considerable attenuation of the risk for red blood cell transfusions28.