Improving the Armamentarium of PI3K Inhibitors with Isoform-Selective Agents: A New Light in the Darkness.

<b/> Excitement and drug-development efforts aimed at targetable genetic aberrations in the PI3K/AKT/mTOR pathway have declined due to the limited clinical performance of these inhibitors as monotherapies. New, more isoform-selective treatments, such as taselisib, promise to both expand the therapeutic window and increase efficacy. Cancer Discov; 7(7); 666-9. ©2017 AACR.See related article by Juric et al., p. 704. ©2017 American Association for Cancer Research.