The typical phenotype of BL (CD19 + /CD10 + /BCL2-/Ki67 > 95%/TdT-/CD34-/sIg +) with appropriate cytomorphology, demonstration of MYC-R alone, and simple karyotype differentiates MYC/BCL2 “double hit” lymphomas and lymphoblastic leukemia/lymphoma [50]. The gene discussed is BCL2; the disease is lymphoma.