The NPs were compared according to the following criteria: (1) toxicity to neutrophils; (2) interaction with and accumulation in neutrophils; (3) effect on neutrophil activation (increased ROS production and CD11b expression); (4) behavior in the blood vessels of the tumor microenvironment after systemic administration; and (5) routes of extravasation (neutrophil-mediated and non-neutrophil-related). The gene discussed is ITGAM; the disease is neoplasm.