In addition, Quinn et al. [47] reported that mean Hb levels were significantly lower in patients with CRC with uncorrected anemia (no treatment or oral iron) compared to patients with corrected anemia (received 1000 mg of IV FCM) on postoperative day three (9.5 g/dL vs. 10.9 g/dL, p = 0.004). This evidence concerns the gene GSTM1 and anemia (phenotype).