HPSE and cancer: During cancer progression, the enzymatic action of heparanase may contribute to the breakdown of extracellular barriers to cell invasion9, regulate the bioavailability of HS-binding growth factors (bFGF, VEGF, and HGF), create a tumor-promoting inflammatory microenvironment2, and generate bioactive HS fragments which potentiate growth factor-receptor binding and signaling1,5,10–15.