To investigate the characteristics of T cell immunodeficiency in lymphomas, we analyzed the expression features of A20 and its upstream regulating factor mucosa-associated lymphoid tissue lymphoma translocation gene 1 (MALT1) and genes downstream of NF-κB in patients with different lymphoma subtypes, including T cell non-Hodgkin lymphoma (T-NHL), B cell non-Hodgkin lymphoma (B-NHL) and NK/T cell lymphoma (NK/T-CL). The gene discussed is MALT1; the disease is B-cell non-Hodgkin lymphoma.