design: Prior to sample preparation, LNCaP cells were confirmed as mycoplasma negative. LNCaP cells grown to 80% confluency were infected with viral supernatant containing lentiCRISPRV2 with ARIP4 targeting sgRNAs for 24h twice. Cells were selected in 2g/ml puromycin containing medium for 48h, and allowed to recover for 24h. Prior to androgen induction, cells were washed twice in 1xPBS and incubated in charcoal stripped serum supplemented medium for 48h. LNCaP cells were then treated with 1nM R1881 for 5h, washed and harvested in ice cold 1xDPBS. RNA was isolated with Trizol Reagent according to the manufacturers instructions. RNA samples were then sent for PolyA enrichment library construction and high throughput sequencing.