Given that idasanutlin-induced apoptosis is delayed37, and that intermittent dosing schedules (once or twice a week) of idasanutlin induce a reduction in mean tumor volume compared with continuous dosing37, we circumvented fish toxicity by pre-treating GATA3-silenced and control BT-474 cells with idasanutlin (25 μM) or vehicle (DMSO) for 24 h, and 48 h post-siRNA transfection, followed by wash-out. The gene discussed is GATA3; the disease is neoplasm.