This multicenter, phase II study (NCT03872791) aims to evaluate the efficacy and safety of the anti-PD-L1/CTLA-4 bispecific antibody KN046 combined with nab-paclitaxel in the first-line treatment of patients with metastatic triple-negative breast cancer (TNBC). The gene discussed is CTLA4; the disease is triple-negative breast carcinoma.