Comparison of 3metH3K9 levels between resistant and sensitive CLL and healthy cell samples (A) and between each subgroup according to the gender (B). For each type of labeling 40 cells for each subgroup were analyzed. 3metH3K9 was at significantly greater level in CLL than in healthy controls, and up-regulated in resistant compared with sensitive CLL patients (arbitrary units). Differences in the mean areas were considered significant for a p-value < 0.01 by Student's t-test (A) or U-test (B). Comparisons between each CLL phenotype (n = 20) and their control counterparts are given at the bottom of the figure (i.e. RM vs. HM; RF vs. HF; SM vs. HM and SF vs. HF). Results are presented using box-plots with medians (lines inside boxes), 25th and 75th percentiles (limits of boxes), and the 10th and 90th percentiles (whiskers). Outliers are also indicated. RM, resistant male; RF, resistant female; SH, sensitive male; SF, sensitive female; HM, healthy male; HF, healthy female. ****, p < 0.0001; ***, p < 0.001 < p; **, p < 0.01; *, p < 0.05; ns, not significant.