Since we had previously demonstrated that N-terminally truncated ERG expressed from the TMPRSS2-ERG fusion gene is ubiquitinated and degraded (albeit truncated ERG appears to have a longer half-life than full-length ERG as reported in the two recent studies above), it is likely that there are SPOP-independent ubiquitin ligases that target ERG in fusion-positive prostate tumors. This evidence concerns the gene TMPRSS2 and prostate neoplasm.