This system includes the galanin peptide and its receptors GAL1-3-R (which are G protein-coupled receptors) that have been studied in relationship with various tumours, and lately, some immunohistochemistry (antibodies-based) analyses identified GAL1-R in bile duct cells and GAL3-R in cholangiocytes and capillary vessels, while in pCCA, GAL3-R expression may work as a poor prognosis marker according to small-sample-sized studies [100,101]. Here, GAL is linked to neoplasm.