HDAC9 and T-cell prolymphocytic leukemia: Oncomine databasemining of published T-PLL patient gene expression data in relationto healthy T-cells revealed specific overexpression of HDAC6 (1.7-fold) compared to other HDAC family members in T-PLL (Figure 7a).46,59 Interestingly, no increase in HDAC6 expressionlevels was observed in available data sets of patients with othermature or immature T-cell malignancies, including anaplastic largecell lymphoma (ALCL), angioimmunoblastic T-cell lymphoma (AITL), PTCLnot otherwise specified (PTCL-NOS), and T-ALL (Figure 7b), suggesting that HDAC6 overexpression may be specific to T-PLL cancer.