PTEN and cancer: More work is needed to delineate the role of p110δ in cancer and to determine important aspects of its regulation and function such as the possible activation of p110δ at certain cellular locations, the mechanisms by which p110δ regulates its cellular locations, the role of p110δ in cancers cells expressing mutated p110α and/or heterozygously mutated PTEN, the p110δ triggered signaling through effectors other than Akt and last but not least the mechanism that regulates the differential expression of p110δ in different cancer types.