STAT3 and T-cell large granular lymphocyte leukemia: Taking into account the heterogeneity of the disease and the several immunophenotypes that may characterize LGL clone, the aim of this work was to evaluate whether STAT3 mutations might be associated with a distinctive LGL immunophenotype and/or indicative for symptomatic disease in an initial cohort of 101 patients affected by T-LGL leukemia.