A) Flow cytometry of CD69 in CD19⁺ cells in one representative control, mutated and unmutated CLL patient, respectively. B) CD19⁺ B cells from 10 controls and 28 patients were analyzed for CD69 expression. % CD69⁺/CD19⁺ cells in controls vs. all CLL patients, Binet A vs. Binet B+C and mutated vs. unmutated CLL patient. Horizontal lines represent mean values in each group. C) Concordance between IgV_H mutation status and CD69, CD38 and ZAP-70. Individuals with ≥ 20% positive CD19⁺ cells were defined as positive for CD38 and ZAP-70. For CD69, individuals with ≥ 50% positive CD19⁺ cells were defined as “high CD69” and individuals with <50% CD69 were defined as “low CD69”. Percentage deviation from the most similar germline gene is shown. Genes with ≥ 2% deviation (dotted line) were defined as mutated. D) ZAP-70 mRNA expression was analyzed in 22 patients by RT-PCR. Mean ZAP-70/RPLP0 expression±SD in CLL patients with mutated IgV_H genes (n=16) vs. unmutated IgV_H genes (n=6) are shown.