Ca: calcium; Ca (ionized): calcium (ionized Bld gas); PTH: parathyroid hormone; PTHrP: PTH-related protein; Vit D-25: 25-hydroxyvitamin D; CEA: carcinoembryonic antigen; CA 27-29: cancer antigen 27-29; CA 15-3: cancer antigen, breast 15-3; MRONJ: medication-related osteonecrosis of the jaw; AKI: acute kidney injury. The gene discussed is PTH; the disease is acute kidney injury.