Primary risk factors of human gastrointestinal cancer include infection with Helicobacter pylori or other bacterial strains that carry the virulence factor cagA. To elucidate the mechanism that underlies the cagA promotion of cancer formation, the expression of cagA by β-actin or FABP2 has been studied in both wild-type and tp53 mutant zebrafish [77]. This evidence concerns the gene TP53 and cancer.