SERP1 and neoplasm: Given that inflammatory cells play an important role in pancreatic cancer progression [34] and that Serp-1 lacks inhibitory activity for pancreatic cancer cell proliferation in culture, it is reasonable to postulate that Serp-1 is targeting tumor promoting innate immune responses to exert the observed anti-tumor activity in vivo, most likely by impeding uPA-dependent migration of inflammatory cells such as TAMs and MDSCs.