LGLL diagnosis was based on the presence of ≥4/6 criteria: i) chronically elevated LGL count (>0.5 × 109/dL over >3 months), ii) clonal TCR rearrangement, iii) VB expansion, iv) flow cytometric detection of aberrant CTL or NK-cell proliferation, v) STAT3/5 mutation and vi) LGL infiltration of the marrow [5]. This evidence concerns the gene STAT3 and T-cell large granular lymphocyte leukemia.