RSPO1 and cancer: The production of cells within a crypt often occurs from LGR5+ stem cells under the stimulation of R-spondin/LGR5, Wnt/Frizzled, delta/notch and EGF/EGFR systems [18], however the regulatory systems controlling new crypt production and/or wound healing responses have not been identified in normal, adenomatous or cancers intestinal mucosa.