Interestingly, tumor-secreted protein NAMPT acts as a rate-limiting enzyme in the upstream pathway of SIRT1, which restricts the OXPHOS of aged neutrophils (CD45+CD11b+Ly6G+CXCR4+CD62Llo) and prolongs the lifespan of neutrophils by mitophagy. This evidence concerns the gene CXCR4 and neoplasm.