In asymptomatic mothers, maternal testing for anti-SS-A/Ro and anti-SS-B/La should be done if there is a diagnosis of heart block in the fetus/postnatally, as neonatal lupus in a fetus can be the first sign that the mother has anti-SS-A/Ro and anti-SS-B/La antibodies [23]. Here, TRIM21 is linked to systemic lupus erythematosus.