In conclusion, these strong results give confidence that cellular qHTS with RX1 is a valid and valuable TrxR inhibitor screening strategy, promising that focused libraries can be used with cell lines of choice to guide development of cellularly-acting TrxR inhibitors. We suggest that tempered SNAr electrophiles would be a good starting-point for such developments. Certainly, quantitative, robust, and selective cellular TrxR probes, with the HTS-compatibility and high data quality that RX1 has shown across these assays, will be vital to guide progress in this new territory of redox-targeting drugs.