Along the same lines, a significant positive correlation was detected between all peptides of COL16A1 (rho (range): 0.13 to 0.26, P < 0.05), FXYD2 (rho (range): 0.15 to 0.33, P < 0.05) and eGFR in CKD patients (S2 Table). This evidence concerns the gene FXYD2 and chronic kidney disease.