The susceptibility of mammals to diseases can be elucidated by the correlation study between gene polymorphism and disease susceptibility, such as the study on the relationship between P53 anti-oncogene polymorphism, tumorigenesis, and metastasis, to reveal the biologic function difference among individuals from the gene level.[20] Genetic susceptibility to malignant tumors has been extensively studied. This evidence concerns the gene TP53 and cancer.