It has been reported previously that C. sinensis ESP-triggered CCA cell migration/invasion is mediated by ERK1/2-NF-κB-MMP-9 and integrin β4-FAK/Src pathways, suggesting that ESPs may function as detrimental modulators of the aggressive progression of liver fluke-associated CCA [33, 34]. Here, MMP9 is linked to cholangiocarcinoma.