RARG and carcinoma of esophagus: On one hand, RARG is significantly overexpressed in hepatocellular carcinoma, esophageal carcinoma, cholangiocarcinoma, colon cancer and other human cancers and plays an important role in promoting tumor progression through the PI3K/Akt, NF-κB, Wnt/β-catenin and other signaling pathways (19–23).