LGR5 and infectious otitis media: To circumvent this problem and assess whether OSAP induction takes place in the initiation of colorectal tumor development, we used the previously reported gene expression profiles of intestinal epithelial stem and precursor cells isolated from either normal colons or AOM/DSS-induced tumors isolated from Lgr5-EGFP mice exposed to azoxymethane/dextran sodium sulfate [28] (AOM/DSS, dataset GSE46200).