CDH17 and breast cancer: Whereas metastatic colorectal cancer cells lose their capacity to bind collagen type I and preferably bind collagen IV after CDH17 activation of α2β1 integrin [3], melanoma and breast cancer cells retained their binding capacity to collagen I. These differences in collagen-binding capacities between both cadherins are probably due to the fact that liver parenchyma is mainly composed of collagen type IV, while lung parenchyma mostly contains type I and III collagen [20].