Calcimimetic compounds have emerged as valuable therapeutic agents in the treatment of hyperparathyroidism caused by loss-of-function CaSR mutations as well as in parathyroid cancer (Hebert, 2006, Jensen and Bräuner-Osborne, 2007, Nemeth et al., 1998, Saidak et al., 2009). The gene discussed is CASR; the disease is malignant tumor of parathyroid gland.