In a prospective study, individuals with celiac disease were found to face a 3-fold increased risk of future IgAN.[32] Researchers have identified deposits of IgA targeting TG2 in renal tissue biopsies of IgAN patients, both with and without coexisting celiac disease.[33] In a Finnish study, 827 patients who underwent kidney biopsies were tested for serum IgA tissue transglutaminase antibodies, revealing that 4.5% of overall kidney disease cases exhibited tissue transglutaminase antibodies. This evidence concerns the gene TGM2 and celiac disease.