GSTM1 and anemia (phenotype): The difference is that, at the erythrocyte level, the virus enters the red blood cell and interacts with the Hb molecule, but its replication is prevented by the absence of a nucleus while, in erythroblasts, the presence of nuclear material would facilitate viral replication and, in this case, the normal recycling of red blood cells from the spleen to the bloodstream would be inhibited, causing anemia [42].