Enterotoxigenic Bacteroides fragilis (ETBF) strains produce a ~ 20 kDa toxin termed the B. fragilis toxin (bft), a zinc metalloprotease associated with intestinal disease and persistent colitis in humans.53–55 Moreover, several epidemiological studies have demonstrated a higher incidence of ETBF infection in CRC patients,23,52,56,57 suggesting bft may play a causative role in CRC. The gene discussed is PITX1; the disease is colorectal carcinoma.