DKK1 and hepatocellular carcinoma: The transgenic zebrafish HCC (hepatocellular carcinoma) model with conditional expression of human MET and induced ectopic Wnt signaling in hepatocytes (genetic level) was microinjected by human peripheral blood mononuclear cells (PBMCs) with a customized synthetic Notch receptor (synNotch) cascade to express the Wnt inhibitor DKK1 and anti-human MET (cellular level) [57].