CEACAM5 and neoplasm: MeV naturally and preferentially replicates in malignant cells, which facilitates antitumor immunity and tumor lysis.398–401 To improve the cytotoxic activity against tumor cells directed by MeV-activated NK cells, oncolytic MeV vaccines encoding both CD16A on NK cells and carcinoembryonic antigen (CEA) as a model tumor antigen was developed, termed bispecific killer engagers (MV-BiKE).402 MV-BiKE mediated the secretion of functional BiKE from infected tumor cells.