At the same time, the p53 expression caused by DNA damage is regulated negatively by the mdm2 gene; mdm2 is an important regulator of p53 and has the function of degrading p53, and is also involved in tumour growth and metastasis [35].Vargas-Torres et al. [18] studied p21 rs1801270 and rs1059234 genetic polymorphisms in 283 cases of cervical cancer patients and 189 cases of normal people; the results showed that mutant homozygous and heterozygous genotypes of the above two polymorphism loci were risk factors for cervical cancer. This evidence concerns the gene MDM2 and neoplasm.