Cell cycle and apoptosis regulator protein 2, also known as Deleted in breast cancer 1 (DBC-1), and KIAA1967, is a protein which in humans is encoded by the CCAR2 gene.
Recent studies show that DBC1 is an inhibitor of the sirtuin-type deacetylase, SIRT1, which deacetylates histones and p53. DBC1 is likely to regulate the activity of SIRT1 or related deacetylases by sensing the soluble products or substrates of the NAD-dependent deacetylation reaction.