There is emerging evidence of clinical and phenotypic significance of specific mutations in T-large granular lymphocytic leukaemia (T-LGLL).STAT3 mutation, found preferentially in CD8+ T-LGLL and gamma/delta T-LGLL, is associated with neutropenia and poorer overall survival [211–214]. Here, CD8A is linked to T-cell large granular lymphocyte leukemia.