NANOG and colonic neoplasm: The AOM/DSS-treated mice were colonized by clinical colibactin-producing E. coli (CoPEC) reference strain 11G5 or its isogenic mutant 11G5Δpks, which is unable to produce colibactin (the clbQ gene of the pks island has been deleted).38 Expressions of NANOG and OCT-3/4 were greatly increased in colonic tumors collected from mice colonized by 11G5 compared to mice harboring colonic tumor colonized by 11G5Δpks (Figure 1a).