CLDN2 and acute myeloid leukemia: The reason(s) behind the distinct responses of Cyp2e1, Glul and Cldn2 to Wnt signaling are unclear but could involve variable thresholds for Wnt stimulation, synergy of Wnt/β-catenin signaling with other pathways, and/or differences in cellular composition between AML-12 cells and intact hepatocytes.