Inhibitors that target the PI3K isoforms p110α, p110β and p110δ are the most relevant since these isoforms are differentially expressed in glioblastoma.85 While there are some p110α/p110β and several p110δ inhibitors on the market, they have not been evaluated in the clinical setting for glioblastoma. Here, PIK3CA is linked to glioblastoma.