Thioredoxin-2 (TXN2) is a mitochondrial member of the thioredoxin family. Thioredoxin-2 is extensively expressed in adult and fetal tissues. Thioredoxin-2 contains an N-terminal 59 amino acid transit peptide, which is cleaved before translocating to mitochondria. Mitochondrial thioredoxin play important roles in the regulation of the mitochondrial membrane potential and in protection against oxidant-induced apoptosis. Thioredoxin-2 could be involved in the resistance to anti-tumor agents and possesses a dithiol-reducing activity. In addition, Thioredoxin-2 is important at low oxidative stress conditions.