c-Abl levels in CLL cells correlate with Mcl-1 gene expression and STAT3 activation. (A) Quantitative RT-PCR analysis of Mcl-1 mRNA expression in cAbl^high-CLL and cAbl^low-CLL cells (P = .025, n = 14). Mcl-1 levels are presented relative to those of RPL27. (B) Western blot analysis showing pS⁷²⁷- and pY⁷⁰⁵-STAT3 levels in 7 high and 7 low c-Abl expressing CLL cases. (C) Box plot representation of the data in panel B. Clear box plots represent pY⁷⁰⁵-STAT3 levels; and shaded box plots, pS⁷²⁷-STAT3 levels. Statistical significance was performed using Mann-Whitney U test (P = .001, n = 14).