To identify the type(s) of GAG chains associated with SRGN secreted by ESCC cells, GAGs were isolated from the CM of SRGN-overexpressing ESCC cells, and then digested using chondroitinases and heparinases which selectively degrade CS/dermatan sulfate (DS) GAGs and heparin/heparin sulfate (HS) chains respectively. This evidence concerns the gene GALNS and esophageal squamous cell carcinoma.