“…The calcitonin (CT), Class B1 GPCRs (CTRs), are highly expressed on osteoclasts and have been exploited therapeutically for treatment of bone disorders, including Paget’s disease, hypercalcemia of malignancy and osteoporosis [2] , [3] , [4] , [5] . The receptors are also expressed in numerous other cells and tissues including leucocytes and their precursors, the central nervous system, kidney, lung, gastrointestinal tract and reproductive tissues [6] , thereby influencing pain perception, feeding and reproduction, and ion secretion [2] , [7] , though these actions are not well understood.…”