GSTM1 and anemia: Anaemia, defined as circulating haemoglobin (Hb) concentration level below 130 g/l for men and 120 g/l for women (World Health Organization 2008), affects 24.8% of the global population (World Health Organization 2008), and up to 54.4% of cardiac surgery patients (Hung et al. 2011) are anaemic prior to surgery.