GSTM1 and chronic kidney disease: It is commonly observed that anaemia, a condition where the body has a reduced volume of red blood cells, occurs concurrently with CKD and that both conditions deteriorate at a similar rate.44 Consequently, haemoglobin (Hb) levels, a protein found in red blood cells which is responsible for the transport of oxygen around the body, is seen as an emerging CKD biomarker.