CD4 and lymphoma: As shown in Table 1 and Additional file 1 (Figure S2), the study prospectively enrolled 100 adults with treatment-naïve DLBCL, with a median age of 70, 40% of patients being stage IV, 33% showing a high-risk IPI score, 26% having bone marrow (BM) involvement, 26% being the GCB type according to Hans algorithm by IHC stains, 41% having double-expressor lymphoma, and the median absolute count of CD4+ T cells and CD8+ T cells in PB being 506 and 390/μL, respectively.