LGR5 and neoplasm: It has been demonstrated that Lgr5 is the downstream target of WNT/β-catenin pathway, critical for the promotion of GI cancer proliferation which points to the interaction between TGF-β1 and Wnt signaling pathways especially in the view of the fact that LGR5 is highly expressed in tumor tissues with nuclear accumulation of β-catenin [282–284].