CALR and neonatal lupus erythematosus: Neonatal lupus erythematosus (NLE) is an uncommon acquired autoimmune disease caused by the passive transfer of maternal autoantibodies including anti‐Sjögren's syndrome A (Ro/SSA), anti‐Sjögren's syndrome B (La/SSB), ribonuclear protein (RNP), and antiphospholipid (APL) antibodies.1