A genetic predisposition to canine glioma exists, with the protein expression of TP53, MDM2, P21, AKT, PTEN, RB1, P16, MTOR, and MAPK correlated to the specific glioma subtype [12]; moreover, a genome-wide association study followed by regional mapping [13] identified single nucleotide variants in three neighboring genes, DENR, CAMKK2, and P2RX7, which are highly associated with glioma susceptibility [13]. Here, PTEN is linked to central nervous system cancer.