SENP1 and cancer: Positive SENP1 immunostaining was seen in 41.7 % (ERG IHC) and 40.9 % (ERG FISH) of ERG positive cancers but in only 28.6 % and 30 % of cancers without ERG staining and ERG rearrangement, respectively (p < 0.0001 each; Fig. 2).