LGR5 and colonic neoplasm: The colon stem cells, marked by the Wnt signaling enhancers Lgr5 and Ascl2 (Schuijers et al., 2015), are usually confined at the base of the crypt in wild-type and miR-34a-/- mice but became enriched in C. rodentium-induced colon tumors in miR-34a-/- mice (Figure 1D).