DMP1 and lymphoma: K-rasLA lung tumors are different from Eμ-Myc lymphomas in that neither bi-allelic Arf deletion or Mdm2 overexpression were found in any tumors, regardless of the genotype of Dmp1 (Eischen et al. 1999; Inoue et al. 2001; Mallakin et al. 2007).