 The diagnosis of celiac disease was initially based on duodenal biopsies obtained from upper endoscopy. Since 1990, the availability of serological tests has contributed to a different perception of the disease. Serological testing is now considered fundamental for celiac disease screening, even if duodenal biopsies remain the gold standard. Celiac markers usually include anti-TG2 antibodies, anti-endomysium antibodies, anti-gliadin antibodies and anti-reticulin antibodies. Recently, several studies showed that deamidated products of gliadin may enhance T-cell stimulatory activity and improve the reactivity of anti-gliadin antibodies. Thus, detection of anti-deamidated gliadin peptide antibodies has been introduced into the wide spectrum of serological tests for celiac disease. 