CD274 and breast cancer: A previous study reported that by blocking the mevalonate pathway, statins effectively disrupted estrogen receptor expression, cancer cell survival, and proliferation.15 Similarly, in an in vitro study, Choe et al14 found that atorvastatin reduced programmed cell death ligand 1 (PD-L1) expression in breast cancer cells, thus enhancing the efficacy of anti–PD-L1 therapy.