The aim of this paper is to report a comprehensive analysis of the effects produced by a selected group of putative MPTP-targeting drugs (Betulinic Acid, Lonidamine, CD437, see [24] for a review) on a TZM-resistant GBM (IV WHO grade) cell line (ADF cells) that did not show EGFR amplification/overexpression and that has a hemizygous deletion of the PTEN gene. The gene discussed is PTEN; the disease is glioblastoma.