PGRMC1 and ovarian cancer: Similarly, sigma-2/PGRMC1 agonists siramesine, WC-26 and SV-119 caused dose-dependent cell death in mature primary neuronal cultures (Fig. 8C) and in SKOV-3 human ovarian cancer cells (Fig. 8D), measured using fluorescent substrates for caspase-3/7 to detect enzymatic activity, but sigma-2/PGRMC1 antagonists RHM-1, CT0109 and CT0093 did not affect cell viability except at very high concentrations (>100 μM).