Further analysis of normal (lymphoma free) splenocytes from four month old ESPL1+/hyp, p53−/− mice by SKY analysis revealed widespread and clonal chromosomal changes with a composite karyotype 36–70, XY, +3, +12, +14, +15, +19[cp6]/40, XY [15], showing gains in chromosomes 3, 12, 14, 15 and 19 (a representative example of some of the changes shown in Figure 7G). The gene discussed is ESPL1; the disease is lymphoma.