The role of GABAB-R activationfor cell proliferation has been investigated by baclofen administration in different rat cancer models,such as gastric cancer and colon tumor models. The results showed that baclofen reduced the incidentof gastric cancer significantly, and decreased the colon tumor malignancyAdditional in vitrostudies have displayed an inhibitory role of baclofen in tumor cell proliferation and/or migration innumerous cell lines including human pulmonary adenocarcinoma-, pancreatic duct epithelial and small airway epithelial cells. However, certain prostate cancer cell lines where not inhibited after baclofentreatment, and rather enhanced cancer migration probably by promoting matrix metalloproteinase-3production