COL17A1 and neoplasm: Of interest, the tumor-initiating fraction of the CR4 cells overexpressed multiple genes controlling cell-to-cell adhesion, including cadherins (CDH 1, 3 and 17, and CDHR5); intergins (ITGB4); genes encoding tight-junction proteins (CLDN3, 4 and 6, COL17A1 and others); and keratins (KRT19, 20, 23 and KRTAP3-1).