TGFB1 and neoplasm: The discrepancy in susceptibility to neutrophil cytotoxicity in primary versus secondary tumors can be explained in part by cellular functions required for dissemination; metastatic tumor cells become susceptible to neutrophil cytotoxicity following epithelial-to-mesenchymal transition (Gershkovitz et al., 2018b), a process regulated by TGF-β signaling, echoing earlier studies implicating this pathway in neutrophil functional diversity (Fridlender et al., 2009; Sagiv et al., 2015).