FGF23 is regulated at the transcriptional and posttranscriptional levels by several bone mineral factors, including phosphate (via glycerol-3-phosphate and lysophosphatidic acid) (9, 10), calcium, vitamin D, and parathyroid hormone (PTH) (11), and nonmineral factors like anemia, inflammation, and metabolism (12). This evidence concerns the gene PTH and anemia (phenotype).