The remaining STAT3 mutations identified (G618R, N647I, G656ins, Y657dup, and D661Y) were distributed in the most frequent LGLL subtypes at variable frequencies (40% of TCD8+-LGLL, 14% of Tγδ+-LGLL, 25% of CD56−/lo, and 100% of CD56+ CLPD-NK populations). This evidence concerns the gene STAT3 and T-cell large granular lymphocyte leukemia.