Tumor-associated neutrophils(TAN)are key components of the tumor microenvironment(TME)that exert dual regulatory roles in tumor progression through highly heterogeneous functional phenotypes.This review systematically addresses the dynamic balance of TAN in pro-tumor and anti-tumor mechanisms:TAN can directly kill tumor cells or collaborate with immune cells to activate anti-tumor re-sponses;however,in contrast,they can accelerate tumor progression by promoting angiogenesis,remodeling the extracellular matrix,and mediating immune evasion.Studies have shown that the functional heterogeneity of TAN is precisely regulated by multiple signaling net-works within the TME,and that the plasticity transformation of different subsets directly influences tumor progression.In-depth analyses of TAN subset characteristics,transformation mechanisms,and their clinical relevance will provide a theoretical basis for the development of inhibitors targeting pro-tumor neutrophils as well as advance the establishment of precise patient selection strategies for TAN subtype-based immunotherapy.

Tumor-associated neutrophils(TAN)are key components of the tumor microenvironment(TME)that exert dual regulatory roles in tumor progression through highly heterogeneous functional phenotypes.This review systematically addresses the dynamic balance of TAN in pro-tumor and anti-tumor mechanisms:TAN can directly kill tumor cells or collaborate with immune cells to activate anti-tumor re-sponses;however,in contrast,they can accelerate tumor progression by promoting angiogenesis,remodeling the extracellular matrix,and mediating immune evasion.Studies have shown that the functional heterogeneity of TAN is precisely regulated by multiple signaling net-works within the TME,and that the plasticity transformation of different subsets directly influences tumor progression.In-depth analyses of TAN subset characteristics,transformation mechanisms,and their clinical relevance will provide a theoretical basis for the development of inhibitors targeting pro-tumor neutrophils as well as advance the establishment of precise patient selection strategies for TAN subtype-based immunotherapy.