FGF‐23 has also been shown to be expressed in lung tissue of adult mice.(12, 66) The four FGFR isoforms are expressed in the postnatal but also in the adult murine lung,(11, 12) and recent human data showed FGFR4 staining localized in the bronchial epithelium,(19) while mRNA expression of FGFR1 and FGFR4 was found in bronchial epithelial cells from healthy subjects and particularly from patients with cystic fibrosis.(67) Whether the lung expresses α‐klotho is still debated. This evidence concerns the gene FGFR4 and cystic fibrosis.