CD274 and breast carcinoma: A dose dependent loss of detectable surface PD-L1 expression was observed on EMT6 breast carcinoma cells after treatment with M7824, indicating its ability to specifically bind surface PD-L1 and with an affinity similar to that of avelumab, a fully humanized mAb targeting PD-L1 (hereafter referred to as αPD-L1) (Fig. 1A).