Figure 3: TMPRSS2-ERG fusion variants. Numerous variations of the TMPRSS2-ERG fusion have been identified, with the most common being T1- E4. As shown, these variants differ in the exons from TMPRSS2 and ERG found in the fusion. T2-S6,4 is a variant in which the fusion is formed between exon 2 of TMPRSS2 and 95 nucleotides that were shown to be identical to a portion of ERG splice form 6, which is then followed by ERG exon 4. The native transcripts of TMPRSS2 and ERG are shown on top for reference, with TMPRSS2 in green and ERG in gold. Light shading represents untranslated regions; dark shading represents open reading frame. T indicates the last exon of TMPRSS2 in the fusion; E indicates the first ERG exon included.