Activation of lung epithelial TLR3 by RNAs in tumor-derived exosomes via NF-kB and MAPK pathways increased the production of chemokines such as CXCL1, CXCL2, CXCL5, and CXCL12, leading to the recruitment and accumulation of neutrophils for PMN formation (58). Here, CXCL12 is linked to neoplasm.