Leucine-rich repeat-containing G-protein-coupled receptor 5 (LGR-5) is a new target gene that activates the Wnt signaling pathway, facilitates tumor development and tumor cell signal transduction, and is reported in several malignancies such as colorectal cancer [10], ovarian tumors [11], basal cell carcinoma [12], breast cancer [13], and esophageal adenocarcinoma [14]. Here, LGR5 is linked to breast cancer.