GSTM1 and anemia (phenotype): When we compared the median g/dL [IQR] changes in Hb for patients with baseline anaemia initiated on d4T and those on AZT, patients on d4T had a larger increase in Hb: 3.1 [1.8- 4.9] versus 2.5 [1.4- 5.0], p < 0.012).