TrxR-IN-5 (compound 4f) is a potent TrxR (thioredoxin reductase) inhibitor, with an IC 50 of 0.16 μM. TrxR-IN-5 increases the levels of ROS, thus leading to potent antiproliferative effects. TrxR-IN-5 exhibits prominent anticacer and anti-metastasis effects.