However, low incidence of CD8+ T cell lymphoma was observed in B6 transgenic mice overexpressing a wild-type Stat5b (B6.Stat5bTg) despite of undetectable Stat5b phosphorylation and the rate of lymphomagenesis was markedly enhanced by immunization or the introduction of TCR transgenes [1]. This evidence concerns the gene CD8A and T-cell non-Hodgkin lymphoma.