HNF1B and ovarian clear cell cancer: HNF1B over-expression in immortalized endometriosis epithelial cells (hypothesized cell of origin for clear cell ovarian cancer) led to altered morphology and multinucleation of cells (11), while siRNA knock-down of HNF1B led to the induction of apoptosis in clear cell ovarian cancer cells lines (26) and significantly inhibited the proliferation and anchorage-dependent colony formation in the prostate cancer cell lines LNCaP and RWPE1 (13).