STAT3 and cholangiocarcinoma: In line with the findings, IHC analysis of human HCC and CC with a high YAP/TAZ activity showed elevated levels of phosphorylation in EGFR, as well as increased phosphorylation in EGFR downstream molecules such as MEK, AKT, and/or STAT3, suggesting a concomitant activation of YAP/TAZ and EGFR signaling pathways in liver cancers (Fig. 4 and Supplementary Table 1).