The majority of recurrent retroviral integration sites were in the vicinity of genes with well-recognized roles in T-ALL pathogenesis, including (in order of frequency) Myc, Gfi1, Notch1, Myb, Pim1, miR17-92, Ccnd3, Zeb2, and Akt1 (Fig. 1 A). This evidence concerns the gene PIM1 and acute lymphoblastic leukemia.