A. 250K Sty SNP Array data for a subset of ETS genes, (i.e., ELF5, EHF, ETS1, ETV6, and ERG) are presented. ETV6 undergoes hemizygous deletion in about 25% of prostate cancers. ERG is represented by 31 SNP markers and demonstrates an interstitial genomic lesion in approximately half of ERG rearranged prostate cancers. B-C. Custom ETS gene tiling arrays with one marker every 20–30bp were used on four prostate cancer samples. Smoothed log2 ratio signals for the four prostate cancer samples and one control (top frames) demonstrate the heterogeneity of the interstitial deletion between ERG and TMPRSS2 as seen in panel B. LuCap35 is characterized by homozygous deletion of ERG and of centromeric portion of ETS2 (39,150Kb) and by hemizygous deletion from ETS2 to PCP4 (Purkinje cell protein 4) (from 39,150Kb to 40,320Kb). The NCI-H660 cell line shows homozygous deletion starting at exon 4 of ERG to ETS2 (from 38,786Kb to 39,440Kb), followed by hemizygous deletion to TMPRSS2. The homozygous deletion observed in NCI-H660, was confirmed by FISH (D). In panel C, the remaining ETS genes were analyzed. We observed that the hormone naïve metastatic lymph node sample (LN13) demonstrated a partial deletion of ETV6, the second most commonly altered ETS gene, starting at 11,813,084bp (chromosome 12). FISH analysis validated the deletion of the telomeric end of ETV6 (E). In addition to ERG, ETS2, and ETV6, we observed aberrations of other ETS genes (i.e., FEV, ELF1, and ERF).