A literature search showed that some clinical protocols targeting a ketogenic diet as an adjuvant treatment for breast cancer have been reported in recent years, such as a ketogenic diet combined with letrozole for treating estrogen-receptor-positive breast cancer (NCT03962647), a ketogenic diet combined with paclitaxel for stage IV breast cancer (NCT03535701), and a ketogenic diet combined with a low-glycemic and insulinemic diet for the rehabilitation of breast cancer patients (Table 1). The gene discussed is ESR1; the disease is breast cancer.