GSTM1 and anemia (phenotype): For many medical conditions, including certain types of anemia, RBC transfusions are required to supply the body with healthy RBCs and maintain a sufficient level of Hb [4] since vital organs, such as the heart, brain, and kidneys, have a limited ability to increase oxygen uptake during anemia, necessitating RBC transfusions to increase oxygen supply to the tissues [5].