Histidine triad nucleotide binding protein 2 (HINT2) is a mitochondrial protein. This protein is an AMP-lysine hydrolase and phosphoamidase and may contribute to tumor suppression. This protein is a member of the HIT superfamily and Hint subfamily, which are characterized as nucleotide hydrolases and transferases that act on the alpha-phosphate of ribonucleotides. HINT2 regulates steroidogenesis through calcium-dependent and calcium-independent signalling pathways that may serve to maintain a favorable mitochondrial potential. Its role in calcium homeostasis may also contribute to its proapoptotic function in hepatocytes and other non-steroidogenic cells, though the exact mechanism remains unclear.