TMPRSS2 and prostate cancer: In prostate cancer cells, ERG was shown to physically interact with the enzymes poly(ADP-ribose) polymerase 1 (PARP1) and the catalytic subunit of DNA protein kinase (DNA-PKcs), which play a role in ERG-induced transcription in vCaP prostate cancer cell-line overexpressing the TMPRSS2:ERG fusion protein (see Section 10.3.2) [13].