To further evaluate the role of Snail in the TSPAN1-mediated promotion of CCA cell invasion and metastasis, it was knocked down and overexpressed in CCLP1-TSPAN1 and HCCC9810-shTSPAN1 cells, respectively (lenti-shSnail-1 was chosen for the experiment, Additional file 10: Figure S8c). Here, PPFIBP2 is linked to cholangiocarcinoma.