While concurrently inhibiting the GSH and thioredoxin antioxidant systems is already known to produce synergistic cell killing of cancer cells in vitro,42,43 using a combination of BSO and auranofin to achieve this end in vivo might not be an effective therapeutic strategy.43 Our results demonstrate that combining auranofin with cyst(e)inase may represent a more effective approach. Here, TXN is linked to cancer.