Based on these observations, we hypothesized that the Tg(act-TXN)+/0 mice did not show an increase in maximum survival for two reasons: 1) the overexpression of Trx1 in Tg(act-TXN)+/0 mice is significantly reduced with age; and 2) Trx1 could promote cancer development in old age. The gene discussed is TXN; the disease is cancer.