The second group of three mice (Mouse #4, #5, #8) was shown to harbor PIM2 as a secondary proto-oncogene cDNA in addition to MYC. The PIM2 and MYC combination of proto-oncogenes is known to have a synergistic effect on prostate carcinoma [33] and B-lymphoma development [11]. This evidence concerns the gene MYC and prostate carcinoma.