PIK3CA and breast cancer: To our knowledge, this study is the first study to comprehensively evaluate the prognostic significance of TP53mut and PI3K/AKT pathway alterations across BC subtypes using data from the MSK13 and METABRIC cohorts.12,14 Our findings show that both TP53mut and PI3K/AKT alterations significantly worsen survival, independent of the BC subtype and other prognostic clinicopathologic features.