However, mice transplanted with cells expressing both Il-7r and NRAS mutations developed fully penetrative polyclonal T-ALL with an immunophenotype more characteristic of mature disease, including the expression of CD4, CD8, CD3, CD90.2, and TCRβ.89 Furthermore, mice transplanted with thymocytes transduced with Il-7r and NUP98–HOXD13 developed AML.89 Taken together, results from this study suggest that the polyclonal nature of the leukaemic cells might be important for disease development and that different combinations of mutations can result in different disease subtypes. This evidence concerns the gene CD8A and acute lymphoblastic leukemia.