Sec-deficient TR1 has demonstrated pro-apoptotic activity in studies evaluating the role of TR1 in interferon and retinoic acid-induced apoptosis [17], as well as more recent supporting data that has demonstrated Sec-deficient TR1 species (designated SecTRAPs) are by themselves potent initiators of apoptosis in human cancer cell lines [16]. Here, TXNRD1 is linked to cancer.