FAT1 and breast cancer: COL17A1 and other three adhesion molecules (BPAG1, CDHF7, and CD97) show downregulation mainly between the premalignant and stage II cells and between the normal myoepithelial and the premalignant cells in breast cancer [37]; therefore, we guess that the stage-specificity of COL17A1 may exist in pancreatic cancer because of limited samples even if our results did not show a significant association between COL17A1 expression and clinical stage.