The strongest evidence is for Helicobacter pylori CagA, a protein that activates the pro-oncogenic catenin and induces an invasive phenotype [12], and for enterotoxigenic strains of Bacteroides fragilis (ETBF), known to produce the B. fragilis toxin (BFT), whose long-term colonization may increase CRC risk [13]. Here, PITX1 is linked to colorectal carcinoma.