Almost all these recurrent CNAs were shared between the two breeds, suggesting that they are more associated with the cancer phenotype than with breed and a subset suggested involvement of known cancer-associated genes including deletions of the tumour suppressor genes CDKN2A/B, RB1, and PTEN. A small number of abberations were unique to each breed, and the authors speculated that these may contribute to the major differences in tumour location evident in the two breeds [77]. This evidence concerns the gene RB1 and cancer.