Quantitative RT-PCR validation for miR-222, miR148a and miR-21 in independent CLL patients. A) MiRNAs expression in a novel cohort of not responder (NR) and complete responder (CR) patients, before fludarabine treatment, quantified by using TaqMan reverse transcription qPCR. Each expression data is normalized on endogenous U6 RNA levels by 2-ΔCt method. Each sample has been analyzed in triplicate. Data are displayed using vertical scatter plot (GraphPad v.5), bars represent means ± SEM. Two-tailed t-test was used to determine the p-values. B) Prediction of response to treatment in newly diagnosed CLL patients in accordance to a 3 miRNAs-based score. A threshold useful to predict response to therapy was established based on miRNA relative expression. Each patient with a final score >1 was classified as refractory.