MKI67 and neoplasm: More importantly, by using the MM xenograft model, we demonstrated that the combination of lenalidomide with olaparib (Fig. S6E) could significantly reduce tumor size (Fig. S6F-H), inhibit cell proliferation (S6J, K, Ki67 staining) compared with using either drug alone, but has no significant effect on the body weight (Fig. S6I).