FLVCR overexpression in mice results in a mild microcytic hypochromic anemia, suggesting that, since hypochromasia and microcytosis only result from heme or hemoglobin deficiency, FLVCR is needed to maintain heme and globin balance and avoid accumulation of free heme or excess globin in the cytoplasm [32]. The gene discussed is FLVCR1; the disease is anemia (phenotype).