PIK3CA R88Q lies within the PI3K-ABD domain of the Pik3ca protein (UniProt.org). R88Q confers a gain of function to the Pik3ca protein as indicated by increased phosphorylation of downstream targets Akt and S6 (PMID: 18829572) and demonstrates increased transFormation ability in two different cell lines, as compared to wild-type Pik3ca (PMID: 29533785).