Abnormal activation of the PI3K pathway is a common finding in a variety of tumor types, including breast cancer, and the recent BELLE‐2 study of the PI3K inhibitor, Buparlisib, showed promising results in progression‐free survival in combination with endocrine therapy, especially in patients with tumors exhibiting PIK3CA mutations (Baselga et al., 2017). This evidence concerns the gene PIK3CA and breast cancer.