MKI67 and mantle cell lymphoma: The cutoff value for Ki-67 has varied between studies: 30%, 40%, 60%, etc. [19–21] Others have divided MCL patients into 4 proliferation groups, with Ki67 < 20%, 21–40%, 41–60%, and > 60%, and their median survival times were 53 months, 33 months, 19 months, and 13 months, respectively (p < 0.001).