originally designed for genomic amplification (29) and has been widely adopted for chromatin immunoprecipitation (ChIP) and whole-genome DNA microarrays (ChIP-chip) (32, 33) and Virochip (25, 34) experiments, is a simple and relatively unbiased amplification procedure to semiquantitatively measure the fusion variants in a complex sample. Previously, the same simple procedure was used to obtain 83% (25 kb/30 kb) of the SARS coronavirus genome with total nucleic acids isolated from a viral culture (25) . The inclusion within the array of probes derived from individual exons and potential fusion junctions simplifies the breakpoint mapping and increases the confidence of data interpretation (Figures 3 and 4) . In contrast to some reports that used multiple primers targeted to every potential fusion junction in hematological malignancies (35) (36) (37) (38) , we used a single set of primers for target amplification (Figure 1 ). The fusion junctions were subsequently decoded by array. This design significantly reduces the problems associated with primer dimers in the multiplex PCR reaction, and creates more room for future assays to include additional fusion genes. Furthermore, most searches for fusion genes have focused on blood cancers, because the cells can be purified before analysis. The application of the previous methodologies is less useful for highly complex solid tumors that are inevitably admixed with normal cells. For example, a previously reported MLLFusionChip could not be applied to samples with cancer cells of 55-10% in 1 mg of total RNA (39) .