CD274 and neoplasm: To elucidate the presence of CSCs and PD-1/PD-L1-expressing subpopulations in SBC and to further explore the cell heterogeneity and the mechanism of tumor aggressiveness, we performed single-cell transcriptomic analysis, profiled 90,691 single-cell transcriptomes in twelve samples from six patients, and identified several novel potential therapeutic markers for prognosis prediction and targeted therapy.