The progression of the calcification process in CKD is attributed to increased exposure to calcium and phosphorus due to bone metabolic disorders and the imbalance between factors that promote calcification (receptor activator of nuclear factor-κB and receptor activator of nuclear factor-κB ligand) and factors that inhibit calcification (klotho, osteoprotegerin, and fetuin A) [60,62,63]. The gene discussed is KL; the disease is chronic kidney disease.