LGR5 and cancer: Leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5), also known as GPR49, belongs to the G-protein-coupled receptor (GPCR) family of proteins [9,10] and is involved in tumor initiation, proliferation and invasion in several tumors including HCCs as a stem cell biomarker [11] by activation of the Wnt/β-catenin pathway in several cancers including liver, cervical and glioma cancers [12,13,14].