The high expression of the BMI1 protein in glioma tissue samples from canine patients, as well as the antiproliferative effects of BMI1 inhibition by the PTC-209 molecule in several cell lines cultured from spontaneous canine gliomas, has been clearly evidenced, supporting the hypothesis of a potential utility of comparative studies to test new therapies, with benefits for both species. This evidence concerns the gene BMI1 and central nervous system cancer.