LGALS9 and autoimmune disease: However, the mechanism by which Gal-9 and its isoforms/splice variants are regulated at the expression, polyadenylation, posttranslational modification, and secretory levels is by far unclear.[51] A recent study[52] showed that Gal-9 downregulates Th1 and Th17 cell responses and is related to suppression mediated by Tregs in murine autoimmune disease models.