DLK1 and hepatocellular carcinoma: Consistent with HCC development, MUP-uPA/Atf4Δhep livers exhibited elevated expression of mRNAs for HCC markers, epiregulin (EREG), epithelial cell adhesion molecule (EPCAM), glypican-3 (GPC3), CD44, and protein delta homologue 1 (DLK1) (Fig. 5F).