Preclinical data have indicated that PI3Kβ isoform-specific inhibition is more potently effective in cancer cells with PTEN loss [40, 41], and clinical trials involving PI3Kβ-targeted inhibitors GSK-2636771 (GlaxoSmithKline) [42] and AZD8186 (AstraZeneca) [43] are currently ongoing to explore the safety and antitumour activity in patients with tumours characterised by PTEN deficiency or PI3Kβ aberrations. The gene discussed is PTEN; the disease is neoplasm.