Immunohistochemical staining was positive for CD20, LCA, CD10, bcl-6, and mum-1, negative for CD3, PCK, and TdT, and the proliferation index was very high with 95% of the cells Ki-67 positive, indicating a diagnosis of diffuse large B-cell lymphoma (DLBCL) that originated in the liver, since there were no other foci of lymphoma. This evidence concerns the gene MKI67 and lymphoma.