Recent data revealed that zonulin, a biomarker of intestinal permeability found in children with MIS-C in the GI tract, with subsequent trafficking of SARS-CoV-2 antigens into the bloodstream, leading to hyperinflammation29· Myocarditis and/or pericarditis represent infrequent adverse cardiac events observed in adolescent and young adult males following SARS-CoV-2 mRNA vaccination. This evidence concerns the gene HP and myocarditis.