Predominantly, they observed an increase in the cleaved C-terminal fragment of FGF23, which lacks phosphaturic activity (Takenaka et al., 2020), while the FGF23 coreceptor – Klotho – was shown to be reduced in ADPKD patients and DBA/2-pcy mice (Kanai et al., 2018; Takenaka et al., 2020). The gene discussed is FGF23; the disease is autosomal dominant polycystic kidney disease.