CALCR (calcitonin receptor) is a G-protein-coupled receptor that plays critical roles in energy homeostasis, calcium regulation, and metabolic control. The receptor is highly expressed in brainstem regions including the dorsal vagal complex, area postrema, and nucleus of the solitary tract, where it mediates the effects of amylin and calcitonin on feeding behavior and body weight regulation 12. CALCR functions as part of amylin receptor complexes (AMY1-3) when combined with receptor activity-modifying proteins (RAMPs), enabling high-affinity amylin binding and downstream signaling through adenylyl cyclase activation 3. The receptor is essential for the anti-obesity effects of amylin analogs like cagrilintide, with CALCR-expressing neurons in the nucleus of the solitary tract showing sustained transcriptional responses that correlate with long-term weight loss 2. Beyond metabolic regulation, CALCR controls renal calcium handling, where decreased expression promotes hypercalciuria and calcium-containing kidney stone formation through dysregulated calcium excretion 4. Genetic variants in CALCR are associated with body mass index in large-scale human studies and kidney stone susceptibility 56. Additionally, CALCR shows aberrant overexpression in gastric cancer, where it interacts with ANTXR1 to promote tumor growth and metastasis via AKT signaling pathway activation 7.