In order to evaluate the effect of PTX3 expression on fibrosarcoma growth and to characterize its neovascular response and inflammatory infiltrate profile, we took advantage of a murine syngeneic fibrosarcoma cell line (MC17-51) (American Type Culture Collection [ATCC] clone CRL-2799; ATCC, Manassas, VA, USA) and of a transgenic TgN (Tie2-hPTX3) mouse model characterized by the endothelial-specific expression of PTX3 driven by the mouse endothelial-specific receptor tyrosine kinase (Tie2) promoter the Tie promoter [12]. This evidence concerns the gene PTX3 and fibrosarcoma.