JAG1 and hepatocellular carcinoma: KRT19 by itself is not regarded as an oncogene; it is expressed in nonmalignant cells as well; however, it has been confirmed that KRT19 is a critical player in the proliferation and invasive behavior of some subtypes of HCCs.22, 23 The KRT19-associated gene signature showed a strong overlap with that of other previously described more malignant HCC subclasses, such as poor survival or proliferation of HCC subtypes.24 The aberrant expression level of NOTCH1, JAG1, and DTX1 was induced by the absence of KRT19 in vitro as well as the TGF-β signal pathway.