STAT3 and Decreased total neutrophil count: To strength the significance of our results, they were validated on a cohort of 20 patients coming from France, confirming that the CD8+/CD16+/CD56- immunophenotype might have a prognostic value in T-LGL leukemia patients, thus contributing to the identification of patients most at risk of neutropenia, for whom STAT3 mutation analysis is highly recommended.