CD274 and cancer: Here, using NK cells from a cancer patient as effector cells, avelumab mediated appreciable ADCC of both H460 and H441 target cells at an effector:target ratio of 25:1 compared to the isotype control MAb; however, using the same patients NK cells with avelumab, no lysis of either total, PD-L1 negative, or PD-L1 positive enriched PBMC was detected (Fig. 6c).