In the present paper, we analyzed mutations in PI3K (exons 9 and 20) and the PTEN (exons 5 and 6); gene amplification of EGFR, PI3K, and AKT; expression levels of AKT, PI3K, apoptotic proteins (pro-apoptotic BAX and anti-apoptotic Bcl2), and phosphorylation of AKT (S473) and PTEN (S380), in a sample of low- and high-grade gliomas from Colombian patients. The gene discussed is PTEN; the disease is central nervous system cancer.