Post-transplant lymphoproliferative disorders (LPDs) are found in recipients with immunosuppressants, and other iatrogenic immunodeficiency-associated (OIIA) LPDs mainly occur in rheumatoid arthritis (RA) patients treated with low-dose methotrexate (MTX), tumour necrosis factor (TNF) inhibitors, and other biologic drugs, and are infrequent in other types of autoimmune disease [1]. The gene discussed is TNF; the disease is rheumatoid arthritis.