A big drop in haemoglobin level was observed among most patients, albeit no one mentioned the incidence of significant haemoglobin drop, leading to severe anaemia.“....this is very important to follow patients so as to be sure of their Hb (haemoglobin) status after treatment because of what we observed... I can say most patients presented with Hb drop of about 1 to 3 units from the original value”. The gene discussed is GSTM1; the disease is anemia (phenotype).