Targeting the PI3K signaling pathway in cancer

The phosphoinositide 3-kinase (PI3K) pathway is activated in a variety of different human cancers, and inhibitors of this pathway are under active development as anti-cancer therapeutics. In this review, we discuss the data supporting the use of PI3K pathway inhibitors in genetically and clinically defined cancers. This review focuses on their efficacy as single agents and in combination with other targeted therapies, specifically those targeting the MEK–ERK signaling pathway.