Allogeneic stem cell transplant,Recent chemotherapy (cytarabine, idarubicin) and venetoclax (Bcl-2 inhibitor),Active immunosuppression with ciclosporin and methotrexate,Lymphopenia (CD4+ T cells 150/μLCD8+ T cells 460/μLB cells <10/μL), and neutropenia (<0.01 × 109/L). Here, CD4 is linked to lymphopenia.