Bone marrow tissue biopsy was performed, showing CD20 (+), CD79a (+), CD3 (–), CD5 (-), CyclinD1 (-), Bcl-2 (+), Bcl-6 (-), CD10 (-), MUM-1 (+), and Ki67 (+>50%), and a pathological diagnosis of high-grade B-cell non-Hodgkin lymphoma was made. The gene discussed is BCL2; the disease is B-cell non-Hodgkin lymphoma.