CLDN1 and hepatocellular carcinoma: RNA sequencing of these patient xenograft tumors (Supplementary Table 3) revealed an enrichment of epithelial markers such as CDH1, CLDN1, DSP, KRT8 and TJP2 in pERK+ xenografts (Figure 3E), and mesenchymal markers such as TWIST1, CDH12, TCF4 and BMP7 in pERK− xenografts (Figure 3F), suggesting that epithelial-mesenchymal transition (EMT) might account for the loss of sorafenib sensitivity in pERK− HCC xenografts.