AKT1 and glioblastoma: Even though acting downstream the pathway has been proposed as an effective way for GBM-SCs targeting (Bleau et al., 2009), it is worth considering that the phosphoinositide 3-kinase (PI3K)/AKT pathway inhibitor enzastaurin failed to demonstrate superiority over lomustine in a phase III trial conducted in patients with recurrent GBM (Wick et al., 2010).