KRT19 and hepatocellular carcinoma: The IGF signalling pathway is also implicated in cancer stemness of HCC as a high ratio of the insulin receptor isoform A (IR-A) to isoform B (IR-B) was associated with a higher expression of the hepatic progenitor cell (HPC) marker, CK19, and poorer overall survival,34 and there was enhanced IR-A expression in spheroid cultures.