CD274 and breast cancer: In the orthotopic EMT-6/CDDP breast cancer model—where in vivo PD-L1 expression was widespread within primary tumours and even more prevalent within lung metastases—single-agent anti-PD-L1 was highly effective in the adjuvant therapy setting, while combining anti-PD-L1 with paclitaxel chemotherapy was beneficial in the neoadjuvant therapy setting.