The Peto paradox is a model that states that body size is not associated with lifespan between species in cancer occurrences. One of the leading hypotheses in the explanation of this model is that it will undergo adaptations to prevent cancer formation in large-bodied animals. Tumor suppressor genes play an important role in many events such as cell cycle control, correction of DNA and chromosomal errors, directing the cell to apoptosis in cases of irreparable damage, and prevention of metastasis. Studies have shown that mutations in tumor suppressor genes trigger cancer formation. In our study, P53, MSH2, CADM1 and NOTCH1 proteins, which play a role in the regulation of various cellular events as tumor suppressors, were studied on this hypothesis. As a result of the bioinformatics studies, the creatures living in large polar regions showing homology similarities with humans were determined using the NCBI database. Considering the alignment results of the relevant proteins, it was determined that the homo sapiens P53 protein similarity rate was low in Ramazzottius varieornatus and alaenoptera musculus species. Considering the alignments of MSH2, CADM1 and NOTCH1, it was determined that these proteins have a high similarity rate between Homo sapiens species and Balaenoptera acutorostrata scammoni species. Keyword: Cancer, peto paradoksu, P53p, Homo sapiens, bioinformatic