Vickery et al also showed median concentrations that were weaker than ours, with a median BNP of 48 ng/L and 576 ng/L for CKD stage 4 patients, and 73 ng/L for BNP and 1636 ng/L for NT-proBNP in stage 5 CKD [22]. This evidence concerns the gene NPPB and chronic kidney disease.