Calcitonin gene-related peptide (CGRP) receptor is a G-protein coupled receptor with three components: calcitonin receptor-like receptor (CALCRL), receptor activity-modifying protein (RAMP1) and CGRP-receptor component protein (CRCP). RAMP1 is required for both the trafficking of the calcitonin-like receptor to the plasma membrane and the coupling of the receptor with CGRP agonist. CRCP is involved in the association between the CGRP receptor and the G protein. Upon ligand binding, the complex interacts with the G protein, the Gαs subunit dissociates from the complex and activates adenylyl cyclase, which produces cAMP. Elevation of the intracellular concentration of cAMP stimulates cAMP-dependent signaling pathways, ultimately resulting in transcription factor cAMP response element binding protein (CREB) to bind to the CRE promoter and induce gene expression. Recombinant HEK293 cell line stably expressing full-length human Calcitonin receptor-like receptor (CALCRL/CRLR/CLR; accession number: NM_005795) and containing a firefly luciferase gene under the control of multimerized cAMP response element (CRE). This cell line can be used to measure the EC50 and IC50 of CALCRL agonists and antagonists using the luciferase reporter activity.