Radiation induced chromosomal aberrations in normal and CML CD34⁺ cells. The figures compare the frequency of chromosomal aberrations in CD34⁺ cells from normal persons and CML patients after exposure to radiation (2 Gy) at first cell division and after 3 or 4 cell divisions, as shown in Table 1 and supplemental Tables 1 and 2. (A) Frequency of total number of aberrations detected using the 2 sets of probes for chromosomes 1, 5, and 11 (shown in blue) and 3, 7, and 21 (shown in red). Differences in frequency of aberrations between normal and CML CD34⁺ cells are shown. (B) Frequency of stable (shown in blue) and unstable (shown in red) chromosomal aberrations. P values for differences in frequency of unstable aberrations between normal and CML CD34⁺ cells are shown.