LGR5 and esophageal squamous cell carcinoma: Overexpression of LGR5 is associated with metastasis in CRC [12, 40, 45, 76, 82, 86, 104–107, 111, 118], breast [63, 74, 119, 115], ESCC [39], lung [13, 109], gastric [113], thyroid [110], and ovarian [38] cancer.