Madison et al. examined the expression levels of let-7 microRNAs and intestinal stem cell markers (e.g., LGR5, EPHB2, and ASCL2) in human CRC tissues and normal adjacent tissues. Let-7a and let-7b were significantly downregulated in CRC specimens, while intestinal stem cell markers were significantly upregulated, which suggests that depletion of let-7a and let-7b may contribute to a stem cell phenotype in CRC [31]. This evidence concerns the gene ASCL2 and colorectal carcinoma.