POU5F1 and ovarian cancer: Here, we show that the human POU5F1P3 pseudogene derived lncRNA, hOCT4P3, is a functional homolog of the murine Pou5f1P4 lncRNA in OVCAR-3 ovarian cancer cells, demonstrating evolutionally constraint on pseudogene–lncRNA-mediated epigenetic silencing of OCT4. Performing mOct4P4 lncRNA pulldown experiments and a mOct4P4 lncRNA deletion analysis we demonstrate that the RNA binding protein FUS and a 200 nucleotide mOct4P4/hOCT4P3 region are essential for Oct4/OCT4 silencing in mouse and human cells.