PIK3CA and breast cancer: In all datasets we aimed to establish if there were genomic mutations enriched in PIK3CA-mut/gain tumors compared to PIK3CA-mut/neut and found that TP53 mutations were indeed significantly enriched (q value < 0.05) in primary PIK3CA-mut/gain BC samples from METABRIC and MSK-2018 while only a borderline significant association was found in TCGA (q value = 0.06).