To test the hypothesis that particular genetic variants of the KL gene could contribute to the existence of unexplained and resistant hyperphosphatemia in certain CKD patients, we addressed the sequencing of the coding region and promoter of KL in two groups of 20 dialyzed patients matched for age and gender, with comparable values of dialysis dose and daily protein intake, that were differentiated only regarding a normal (<1.60 mmol/L) or high (>1.60 mmol/L) serum phosphate levels. This evidence concerns the gene KL and chronic kidney disease.