In particular, by means of both ERK5 chemical inhibition and silencing experiments, we demonstrated that ERK5 activity is required for (i) the maintenance of YAP-dependent gene expression both in liver stem cells and in hepatocellular carcinoma cell lines, (ii) the YAP activation in cell adhesion dynamics and TGFβ-induced EMT, and (iii) the YAP-dependent cell migration. This evidence concerns the gene TGFB1 and hepatocellular carcinoma.