Both were in women with breast cancer – one had a triple negative breast cancer (ER and progesterone receptor (PR) negative, HER2 negative) that was PIK3CA wild type, without PTEN loss and KRAS mutant; and the other had a ER/PR positive, HER2 negative tumor with a confirmed PIK3CA mutation (E545K). The gene discussed is ESR1; the disease is breast carcinoma.