BCL2 and B-cell non-Hodgkin lymphoma: Although previous attempts were made to generate a model of DHL by intercrossing Eμ-Myc with Eμ-Bcl-2 transgenic mice19, these tumours were identified as immature haematopoietic progenitor tumours with no Ig or Tcr gene rearrangements and did not represent classical B cell lymphomas.