FGF23 and chronic kidney disease: In Klotho analyses, we could observe such similar cases, in which studies with non-CKD populations showed a negative direction of effect sizes, i.e., Koga61 and Morita31 in Fig. 2D and Jeong63, Keles64, and Keles65 in Fig. 2E. These findings indicated that FGF-23 and Klotho play important roles as a promoter and inhibitor, respectively98, in both CKD and non-CKD patients, and are not being entirely affected by kidney function status.