LGR5 and colorectal carcinoma: The Lgr5 cancer stem cell possibly involves the pathogenesis, progression, and metastasis of CRC, because the expression of Lgr5 was significantly associated with cancer grade, the depth of tumor invasion, perineural invasion, lymph node metastasis, distant metastasis, pTNM stage and Ki-67 expression, as shown in our and other studies [6, 10, 11].