STAT3 and neutropenia: Despite this, statistically significant differences were observed between both groups of T/NK-LGLL patients as regards the frequency of neutropenia (32% vs. 13%, p = 0.04)—particularly of severe (<500 neutrophils/μL) neutropenia (14% vs. 0%, p = 0.02)—and the platelet count in blood (mean ± SD: 203 ± 88 vs. 243 ± 72 platelets × 109/L respectively, p = 0.05), which were more frequently altered in STAT3-mutated vs. unmutated cases (Table 3), while hemoglobin levels were significantly reduced only in non-Y640F STAT3-mutated cases vs. WT cases (11 ± 2.2 vs. 13 ± 2.1 g/dL respectively, p = 0.001).