Exosomes play a pivotal role in intercellular communication and are instrumental in PMN formation in the liver.235 In pancreatic cancer liver metastasis, macrophage migration inhibitory factor (MIF)-containing exosomes can specifically activate Kupffer cells in the liver under the mediation of αvβ5 integrin, thereby inducing the secretion of TGF-β and promoting tumor-specific liver metastasis.182 In addition, hepatocytes can respond to cytokines secreted by tumors, such as IL-6, by producing myeloid cell chemoattractants, such as serum amyloid A (SAA). Here, MIF is linked to neoplasm.