To directly elucidate the fate of excessively aging neutrophils in cancer, we isolated aged neutrophils from tumor-free mice treated with blocking anti-P-selectin and anti-E-selectin antibodies which effectively interferes with the elimination of chronologically (and biologically) aged neutrophils in bone marrow, liver, and spleen, thereby enriching BrdUneg CXCR4hi (aged) neutrophils in the systemic circulation (90.2%±2.6% aged neutrophils of total neutrophils). The gene discussed is SELP; the disease is neoplasm.