The characteristics of the mutations found by target sequencing of the 8-gene panel were similar to those observed in other series of BC, with classical hotpots found in AKT1 and PIK3CA, a majority of missense mutations found in TP53, a higher proportion of truncating TP53 mutations in TN cases compared with other subtypes, and an expected distribution of mutated genes within IHC subtypes. This evidence concerns the gene PIK3CA and breast cancer.