CCKAR and melanoma: This signaling pathway is activated upon the transition of a latent form of TGFβ1 to an active form that binds the heteromeric receptor TGFβRI.10, 11 Meanwhile, tumor-cell collagen gene expression also requires CCKAR-induced AKT activation, which enhances pSMAD3 signaling and its associated collagen expression.12 CCKAR, a G protein-coupled receptor of cholecystokinin, is highly expressed in cancer cells of many types, including gallbladder cancer,13 melanoma,14 pancreatic cancer,15 and non-small cell lung cancer,16 and is associated with poor prognosis.