GSTM1 and anemia (phenotype): The serum Hb value in the subject group varied between 2.6 g/dL and 17 g/dL. At diagnosis, 18 (7.2%) patients had severe anemia, 32 (12.9%) had moderate anemia, 58 (23.3%) had mild anemia, and 141 (56.6%) had no anemia at all at the time of diagnosis.