The anti-tumor mechanisms of neutrophils include: (a) N1 neutrophils directly kill tumor cells by releasing reactive oxygen species (ROS) and reactive nitrogen (RNS); (b) As antigen-presenting cells, neutrophils can directly stimulate T cell activation, and simultaneously release a variety of chemokines such as TNF-α, and cathepsin G to activate DCs, macrophages, NK cells, and T cells. This evidence concerns the gene CTSG and neoplasm.