CD79A and celiac disease: A simple rule by Catassi and Fasano suggests that the diagnosis of CD is confirmed if at least four of the following five criteria are satisfied: (1) typical symptoms of celiac disease; (2) positivity of serum celiac disease IgA class autoantibodies at high titer; (3) HLA-DQ2 or DQ8 genotypes; (4) celiac enteropathy at the small intestinal biopsy; and (5) response to the GFD (three out of four if HLA is not performed) [17].