Hypercalcemia of malignancy is usually caused by osteolytic processes of metastases, production of parathormone-related peptide, or secretion of 1,25-dihydroxyvitamin D. Here, we present a case of ectopic PTH production by malignancy and have identified further 11 published cases in the literature. The gene discussed is PTH; the disease is hypercalcemia disease.