miR-15a and miR-16 target Mcl1 but not Bcl-2 in primary CLL cells. (A) Expression of miR-15a and miR-16 in a CLL sample after nucleofection for 48 hours. (B) Levels of Mcl-1 and Bcl-2 in a CLL sample after nucleofection with miR-15a, miR-16, or a scrambled nontargeting control (Scr) miR for 48 hours. (C) Quantitation of the levels of Mcl-1 and Bcl-2 in 10 primary CLL samples after nucleofection with miR-15a, miR-16, or a Scr miR for 48 hours. Statistical significance of the decrease of Mcl-1 and Bcl-2 levels was determined by 1-way ANOVA.