Finally, because we were unable to discriminate between ETA- and ETB-mediated effects in the current study and to highlight the clinical importance of our findings, we analyzed FWC in one of our previous studies.24 Here, in both healthy volunteers and those with CKD, we have demonstrated that selective ETB receptor antagonism, but not selective ETA or mixed ETA/B blockade, diminishes the capacity to clear free water (Figure S5). This evidence concerns the gene EDNRB and chronic kidney disease.