When the two conditions concur, serum markers for CD (IgA antibodies to tissue transglutaminase and endomysium) have been found to be present in 60% of T1DM patients (who are going to develop CD in the future) at diabetes onset; Barera et al. (2002) also reported that an estimated 40% of subjects suffering from T1DM develop CD after diabetes onset (13). This evidence concerns the gene TGM2 and diabetes mellitus.