Considering the higher technical reproducibility of the assessment by U/dL rather than OD, we used anti-DSG2-ab U/L as reference values (+2 standard deviations) for classifying patients as anti-DSG2-ab-positive (cut-off 5.12 U/L): ARVC patients were anti-DSG2-ab-positive in 51% of cases (39/77), and myocarditis/DCM patients in 48% of cases (44/91). The gene discussed is DSG2; the disease is familial dilated cardiomyopathy.