Thus, we found cases in which tumor cells were homogeneously double positive for those markers (Figure 2C, animal #1), cases in which the leukemia/lymphomas were composed of two separate CD4+CD8+ and CD8+ populations (Figure 2C, animal #2), and cases in which single CD8+ cells were observed in the tumor cell population (Figure 2C, animal #3). This evidence concerns the gene CD4 and leukemia.