Expression of intracellular GLUT1 is diminished in CLL-derived CD8⁺ T cells. CD8⁺ T cells were sorted (A,E) from PBMCs from CLL patients and age-matched HDs or were left in their PBMC fraction (B-D), and analyzed for basal (A) extracellular acidification rate (ECAR; indicating glycolysis; CLL, n = 8; HD, n = 10), (B) glucose uptake, (C) total expression of GLUT1 (intracellular plus surface; CLL, n = 4; HD, n = 4), (D) HIF-1α expression (CLL, n = 4; HD, n = 4), and (E) GLUT-1 mRNA (CLL, n = 8; HD, n = 7). Normality was determined by a D’Agostino and Pearson normality test. The P value was calculated by a Welch test (A,C), Mann-Whitney test (B,D), or an unpaired Student t test (E). Data are presented as mean plus or minus SEM. *P < .05.