CD177 and neoplasm: In addition to the presence of different subsets of neutrophils, such as N1/N2 or low-density neutrophils/high-density neutrophils (LDN/HDN) in tumor tissues (27, 28), the heterogeneity of neutrophils has also gradually been recognized in tumor, such as antigen presenting cell-like (29), SiglecFhi (30), CD13+ (31), CD177+ (32), c-MET+ (33), PD-L1+ (34), IL-17+ (35), iNOS+ (36).