Up-regulation of CD1 and c-myc in CD34⁺ cells of patients with trisomy 8. CD34⁺ cells from the BM of patients with trisomy 8 were separated by flow cytometry, and mRNA was extracted and subjected to real-time PCR as described in “Materials and methods”; FISH was also performed to determine the percentage of trisomy 8 cells in the same sample. Both c-myc and CD1 m-RNAs were up-regulated in trisomy 8 compared with a control group of 10 healthy donors (A). The magnitude of increase in c-myc and CD1 expression was proportional to the number of trisomy 8 CD34 cells in the sample (B-C). Error bars represent standard error of the mean (SEM).