Col4a3KO animals showed decreased circulating iron, ferritin (as a measure of iron stores), hemoglobin, red blood cell number, hematocrit, and mean corpuscular volume consistent with the development of microcytic anemia (Fig. 3a–h).2 Deletion of Lcn2 in Col4a3KO mice partially corrected circulating iron, transferrin saturation, and ferritin levels, suggesting that increased levels of LCN2 contribute to disordered iron metabolism in CKD (Fig. 3a–c). This evidence concerns the gene LCN2 and chronic kidney disease.