At same time, lower or weakly positive rate of Bcl-2 (<20%) could support the diagnosis of BL, which is tally with the results of our study (6/43, 13.95%).[18] Apart from Bcl-2, the proportion of patients with a Ki-67 level ≤95% (10 cases) was lower in adolescents and adults than that in children. This evidence concerns the gene MKI67 and Burkitt lymphoma.