ANXA2 and Patent ductus arteriosus: However, ANXA2 is normally a cytoplasmic and lumenalresiding protein in pancreatic tissue, and previous studies[9] have not determinedwhether cell surface ANXA2 expression is a dominant pattern in PDA tissues.Therefore, we analyzed the location of ANXA2 expression by immunohistochemistry(IHC) in the resected tumors from 52 of the 60 patients treated in our Phase IIstudy for whom specimens were available for staining.