Evaluation of hypercalcemia begins with assessment of serum levels of calcium, ionized calcium, PTH, PTHrP, and 1,25-dihydroxyvitamin D. In the setting of paraneoplastic hypercalcemia, laboratory results reveal increased calcium levels, low-to-normal PTH levels, and unusually high PTHrP [5]. This evidence concerns the gene PTH and hypercalcemia disease.