A meta‐analysis identified several important risk factors for NPSLE, including leukopenia, thrombocytopenia, elevated alanine aminotransferase and aspartate aminotransferase levels, fever, vasculitic skin lesions, elevated ESR, low C3 and C4 levels, and positive antiphospholipid antibodies (APL).20 Here, C4A is linked to acute promyelocytic leukemia.