In both patients with and without DM, serum FGF23 was positively correlated with calcium (r = 0.36 and 0.31), phosphorus (r = 0.27 and 0.45), and calcium × phosphorus (r = 0.37 and 0.52), while fetuin-A was positively correlated with albumin (r = 0.27 and 0.25). The gene discussed is FGF23; the disease is diabetes mellitus.