Interestingly, out of 16 tumors isolated from TAM-injected mice, only 5 were B-cell lymphomas (B220+), out of which 4 were escapees (2 expressed PRDM15 in the nucleus, 2 expressed PRDM15 in the cytoplasm) and only one had undetectable levels of PRDM15. This evidence concerns the gene PRDM15 and B-cell non-Hodgkin lymphoma.