(A) Analysis of a purified plasma cell of MGUS individual no. 16, using the Y6, IG10, and 13q32 probes. The yellow signal corresponds to the fusion of 1 green (IG10 probe) and 1 red (Y6 probe) on a normal chromosome 14. The second chromosome 14 is rearranged, because the Y6 and the IG10 probes are separated. This clonal plasma cell is disomic for chromosome 13 (2 white signals). (B) Another plasma cell of the same patient. In contrast to the cell shown in (A), this clonal plasma cell (with an illegitimate IGH rearrangement) displays deletion 13q (only 1 white signal).