This includes an ongoing Phase I/Phase II study where this molecule is used in combination with paclitaxel in patients with advanced HER2-negative breast cancer (clinical trials USA government identifier NCT03568422) and an independent study where CFI-402257 has been used in combination with the drug fulvestrant in breast cancer patients (clinical trials USA government identifier NCT05251714). The gene discussed is ERBB2; the disease is breast carcinoma.