Furthermore, blocking PI3K is also proposed to treat HER2-positive breast cancer [14] and exert synergistic effects in combination with trastuzumab for the treatment of anti-HER2-resistant breast cancer with either a PIK3CA mutation or loss of PTEN expression, where the therapeutic effectiveness is higher in PIK3CA-mutant cells [15]. The gene discussed is PTEN; the disease is breast carcinoma.