PTH and hypercalcemia disease: The long-acting PTH (LA-PTH, a modified PTH1–15/PTHrP16–34 chimera) that induces a prolonged endosomal cAMP production in cells also triggers prolonged production of the active vitamin D, bone formation, and hypercalcemia when injected in mice and monkeys, compared with elevations mediated by PTH1–34 (reviewed in Ref.