MKI67 and neoplasm: Immunohistochemistry revealed the tumor cells to be positive for CD20 (Fig. 7a), CD79a (Fig. 7b), bcl-2 (Fig. 7c), and MUM1 (Fig. 7d), but negative for CD3 (Fig. 7e), CD10, bcl-6, and cyclin D1, with a Ki-67 labeling index (Ki-67 LI) of 16% (Fig. 7f).