We next tested effects of increasing concentrations of DNA (20-1000 ng) encoding SENP1, SENP1m and SENP2 on PRE2-Luc transcription by R5020-liganded, wild-type PR-B transiently expressed in HeLa cells (Figure 2B) or stably expressed in T47D breast cancer cells (Additional file 1: Figure S1B). This evidence concerns the gene RB1 and breast cancer.