MKI67 and benign neoplasm: Long et al. (2006) found a significant difference in Ki-67 expression between benign and anaplastic tumors, with benign tumors having a mean Ki-67 LI of 0 (range of 0–2.0), while anaplastic meningiomas expressed a mean Ki-67 LI of 19.3 (range of 13.0–41.1).