B3GAT1 and T-cell large granular lymphocyte leukemia: In T-LGLL patients, the dominant CD8+ TCR-Vβ+ expansions displayed a classical antigen-driven phenotype, reflected by significantly higher expression levels of CD57 and 2B4 and significantly lower expression levels of CD27 and CD127 compared with the residual CD8+ TCR-Vβ− populations (Fig. 3A, top panel).