As a result of intensive studies, the present inventors succeeded for the first time in finding that by inhibiting sulfation at the 4- or 6-position of GalNAc which is one of the sugars constituting a sugar chain, tissue fibrogenesis at a biological level can be suppressed. Further, the present inventors succeeded in demonstrating that an inhibitor of sulfation at the 4- or 6-position of GalNAc has a therapeutic effect on a disease caused by tissue fibrogenesis (fibrogenic disease) from studies using various disease model animals.
