The final diagnosis of SLE with secondary antiphospholipid syndrome was made after taking into account the various clinical manifestations (inflammatory joint pains, abnormal rash, peripheral polyneuropathy, cauda equina syndrome, pulmonary embolism), blood investigations (leukopenia, lymphopenia, anemia, low complements), serological investigations (positive ANA, anti-dsDNA, anti-Sm, anti-ribosomal P protein, anti-β2-glycoprotein antibody), nerve conduction studies, and radiological imaging (leptomeningeal enhancement of cauda equina region). Here, BTG3 is linked to lymphopenia.