This may be due to the fact that the extracted GAG-pools contain the total PG pool of GAGs, i. e. not only the GAGs from serglycin, and suggests that other proteoglycans potentially compensate for the lack of serglycin or that the contribution of serglycin proteoglycans to the total level of GAGs in tumour tissue is relatively small. The gene discussed is SRGN; the disease is neoplasm.