As is the case for somatic mosaic overgrowth-associated variants in PIK3CA and AKT1, mosaic PIK3R1 variants are also found in cancer.21PIK3CA is more commonly altered in cancer in comparison to PIK3R1. Among 181 studies with nonredundant samples curated in cBioPortal encompassing in total 47,580 samples, 10.3% harbored a PIK3CA variant, as opposed to 2.1% for PIK3R1 (date accessed 11 November 2020). This evidence concerns the gene PIK3R1 and cancer.