CALR and neonatal lupus erythematosus: Indeed, fibrotic replacement of the atrioventricular (AV) node and endocardial fibroelastosis in the late second trimester of pregnancy are histopathological lesions characterizing cardiac manifestations of neonatal lupus (cardiac-NL), also referred to as congenital heart block (CHB), associated with the transplacental passage of maternal anti-SSA/Ro antibodies (1).