This drug has efficacy in clinical trials for the treatment of breast cancer in patients with epidermal growth factor receptor 2-positive (EGFR+), hormone receptor-negative (HR–), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic (PI3KCA) or AKT mutations and/or Phosphatase and Tensin Homolog deleted on Chromosome 10 (PTEN) loss/PTEN mutations (Xing et al., 2019; Chien et al., 2020). This evidence concerns the gene PTEN and breast cancer.