Expression profiles of SAMHD1 in primary CLL cells. (A) cDNA pools from B cells (CD19⁺, CD5⁻) sorted from peripheral blood of healthy donors and SAMHD1-mutated CLL cells (CD19⁺, CD5⁺) were subjected to quantitative PCR analysis using ABL as a control gene. (B) Measurement of SAMHD1 mRNA by quantitative RT-PCR. The percentage of leukemia cells (CD5⁺/CD19⁺) is indicated. Statistical comparison of SAMHD1 mRNA levels between each CLL sample and the mean of the healthy PBMCs was performed. The black bars indicate P < .01. (C) Measurement of SAMHD1 protein levels by western blot in 10 CLL samples and 7 healthy PBMCs. Ponceau dye staining was used to control protein load.