However, a number of small molecules, including hydrogen peroxide, part-henolide, arsenic trioxide, phenethyl isothiocyanate, auranofin [a thioredoxin reductase inhibitor], buthionine sulfoximine [a γ-glutamylcysteine synthetase inhibitor], and decyl-triphenylphosphonium, that were previously shown to kill cancer cells by inducing oxidative stress were not able to selectively kill IR-SCs [25]. The gene discussed is PRDX5; the disease is cancer.