MERTK and neoplasm: As expected, M2 macrophages without treatment could hardly phagocytize living tumor cells (M-LC group) but cleared about 80% of apoptotic tumor cells (M-AC group), and OMVs treatment (M-AC + OMVs group) cannot alleviate this clearance because strong PtdSer signaling bridging to MerTK would induce active efferocytosis (Fig. 2c–e).