The importance of HSPG structure in tumor biology was demonstrated in a study where Liu et al. injected bacterial recombinant heparinase (Hep) I (which cleaves highly sulfated regions) and Hep III (which cleaves unsulfated regions) into melanoma challenged mice and found that the specificity of the enzymes dictated whether tumors regressed (Hep III) or advanced (Hep I) due to where the different enzymes cleaved HS (214). Here, HSPG2 is linked to neoplasm.