To further dissect the role of CD70 in B‐cell malignancies, which hypothetically could be either tumour suppressive or oncogenic, we conducted a comprehensive study to investigate the functional and clinical relevance of genetic alterations in the CD70 gene and the protein expression pattern of CD70 in two independent cohorts of DLBCL patients with different ethnic backgrounds and viral infection statuses. This evidence concerns the gene CD70 and viral infectious disease.