<h4>Background</h4>Diffuse large B-cell lymphoma (DLBCL) exhibits immunological heterogeneity that influences outcomes of immunochemotherapy, with CD8+ T cells playing a critical role in patient prognosis.<h4>Methods</h4>We integrated single-cell and bulk transcriptome data to establish a CD8+ T cell-associated prognostic signature. The gene discussed is CD8A; the disease is diffuse large B-cell lymphoma.