These tumors tend to have several unique characteristics, including the absence of androgen receptors and PSA production and the presence of a variety of growth factor receptors (i.e. bombesin, somatostatin, chromogranin-A, serotonin and Parathyroid hormone (PTH)).[30] This leads to a clinical presentation quite different from AIPC, with more frequent visceral and soft tissue metastases, osteolytic bone metastases, brain metastases, hypercalcemia and a rapid clinical deterioration. The gene discussed is PTH; the disease is hypercalcemia disease.