KRT19 and liver cancer: To assess whether our orthotopic PDX models preserve these epithelial features, we performed immunohistochemical staining for representative epithelial markers including E-cadherin (ECAD), cytokeratin 19 (CK19/KRT19), and cytokeratin 18 (CK18/KRT18) on liver cancer tissue sections from orthotopic xenografts (Fig. S5A).