FGFR1 and chronic kidney disease: Plasma phosphate levels were significantly increased in CKD mice: Fgfr1–3flox/flox, control (6.3 ± 0.4 mg/dL, n = 10) vs CKD (13.8 ± 1.6 mg/dL, n = 9), P < 0.001; αKlothoflox/flox, control (6.5 ± 1.0 mg/dL, n = 18) vs CKD (12.7 ± 2.4 mg/dL, n = 11), P < 0.001;Fgfr1–4flox/flox, control (8.5 ± 1.7 mg/dL, n = 11) vs CKD (17.2 ± 3.2 mg/dL, n = 8), P < 0.001.