Workup for his hypercalcemia revealed a normal intact parathyroid hormone (PTH) level of 20 pg/mL (Ref: 15–65 pg/mL), though repeat PTH following zoledronic acid infusion was low at 10 pg/mL (Ref: 15–65 pg/mL). The gene discussed is PTH; the disease is Hypercalcemia.