A 50-year-old male patient was diagnosed with DLBCL (non-GCB, stage IV) in December 2018 according to the immunohistochemistry analysis of parotid gland biopsy showing CD19 (+), CD20 (+), CD3 (-), CD5 (-), CD10 (-), CD45 (+), BCL2 (-), BCL6 (+), MUM1 (+), MYC (+) and Ki-67 (+, 90%) (details shown in Table 1). The gene discussed is CD19; the disease is diffuse large B-cell lymphoma.