The mean Hb increase was 1.4 g/dl in the tocilizumab group, which was significantly larger than that for the TNF-α inhibitor group (0.7 g/dl) (P < 0.01), indicating that tocilizumab had a more beneficial effect than TNF-α inhibitors on improvement of RA-anemia. This evidence concerns the gene GSTM1 and anemia (phenotype).