CD274 and neoplasm: In 4T1 murine BC experimental models, the use of a nanodrug that contained metformin and the anticancer agent SN38 (7-ethyl-10-hydroxycamptothecin) resulted in improved outcomes compared to metformin or ICPIs alone, an effect that was mediated by the downregulation of PD-L1 expressed by the tumour cells [123].