Finally, we examine IGFBP-6 in primary liver cancers—hepatocellular carcinoma and cholangiocarcinoma—highlighting evidence for tumor-suppressive versus pro-migratory activities, potential crosstalk with hypoxia, Wnt/β-catenin and TGF-β signaling, and interactions with the tumor immune microenvironment. The gene discussed is IGFBP6; the disease is liver cancer.