CD49d is almost universally expressed by trisomy 12 CLL. The percent of CD49d⁺ cases among 1200 CLL split according to the cytogenetic groups defined by Döhner et al⁴  (A) and in the context of the 17p- and 11q- groups, split according to the presence or not of trisomy 12 (B). 17p-, 17p13.1 deletion; 11q-, 11q22-q23 deletion; +12, trisomy 12; 13q-, 13q14.3 deletion; normal, none of the above. All P values refer to the χ² test. (C) CD49d expression in CLL cases split into 2 groups according to the presence of trisomy 12. Dotted lines were set at 30% and 10% cutoffs, and the number and percentages of cases expressing different CD49d levels are reported. (D) CD49d MFI values in CD49d⁺ CLL bearing or not bearing trisomy 12. Boxes represent the interquartile range (25-75%), with the middle line indicating the median and the horizontal lines indicating the minimum and maximum values. (E) FISH analysis in the total and in the CD49d– and CD49d⁺ sorted components from 3 CLL cases characterized by CD49d bimodal expression. The upper panels represent dot plots of CD19 vs CD49d expression from 1 representative case (case 2). The insets show representative fields of FISH analysis performed with an α satellite DNA probe CEP12, directly labeled with SpectrumGreen to detect aneuploidy of chromosome 12. Histograms represent the percent of trisomy 12 nuclei in the total CD5⁺CD19⁺ (left), CD5⁺CD19⁺CD49d^– (middle), and the CD5⁺CD19⁺CD49d⁺ (right) sorted components from 3 CLL cases.