CKD mice developed severe kidney fibrosis (Figure 1B) and displayed systemic hypoferremia with low serum iron, low transferrin saturation, and high serum soluble transferrin receptor levels, (Supplemental Figure 1; supplemental material available online with this article; https://doi.org/10.1172/jci.insight.159235DS1). This evidence concerns the gene TFRC and chronic kidney disease.