Genetic silencing of HDAC6 in euTCL1 mice. (A) Intracellular HDAC6 protein expression in CD19⁺ B220⁺ B cells from WT or euTCL1 peripheral blood (PB), as determined by flow cytometry (n = 9 per group). (B) Overall survival of indicated groups of mice (n = 5 per group), representing results of 3 independent experiments. (C) CLL burden quantified in PB or spleen by flow cytometry (n = 5 per group), representing results of at least 3 independent experiments. (D) Compilation of spleen weight data at the end of the study (n = 3 per group). (E) Representative spleens from each group indicated. (F) Spleen tyrosine kinase (SYK) messenger RNA (mRNA) expression in aged mice (n = 3 per group) normalized to 18s control gene. *P < .05, **P < .005, ***P < .0005.