TSPAN1 and cholangiocarcinoma: In addition, TSPAN1 protein (Fig. 1f) and mRNA levels (Fig. 1g) were observed to increase gradually in CCA cells with high metastatic potential (KMBC, HCCC9810, and HuCCT1) to CCA cells with low metastatic potential (CCLP1, RBE, and Huh28) and, ultimately, to normal liver (L02) and normal human intrahepatic biliary (HIBEpiC) cell lines [21].