In hemodialysis (HD) patients with secondary hyperparathyroidism, higher PTH levels group had higher apelin levels [1.17 (0.7) ng/ml] compared with lower PTH levels group [0.50 (0.15) ng/ml], and Apelin protects human osteoblasts against apoptosis and induce osteoblast proliferation through competing with the opposite function of PTH [29]. This evidence concerns the gene APLN and secondary hyperparathyroidism.