RRAS and ovarian carcinoma: R-Ras transcripts were evident in the same five MPNST lines with detectable R-Ras protein (Fig. 1b, top) and were present at levels similar to those seen in some cell lines derived from other cancer types (SK-N-MC neuroepithelioma, SK-OV-3 ovarian cancer and U87-MG glioblastoma cells).