According to the immunophenotype of the leukemic clone, two distinct subtypes of T-LGLL can be distinguished: the canonical CD8 + /CD4- T-LGL proliferation (CD8 + T-LGLL) and the less common CD4 + /CD8dim/neg variant (CD4 + T-LGLL) [5], accounting for up to 30% of cases [6]. This evidence concerns the gene CD4 and T-cell large granular lymphocyte leukemia.