In mammals, CTR is widely expressed during foetal10,11 and perinatal12,13 development, in adult14,15 by lymphocytes,16–18 in inflammation associated with wound healing15 and cardiovascular disease19,20 and in several cancers.15,21–25 CTR is the only characterized receptor for calcitonin (CT) and also serves as the signalling protomer in the heteromeric amylin receptor (CTR/RAMP1). Here, CALCR is linked to cancer.