1. Regulatory proteins of the basic helix–loop–helix transcription-factor superfamily; DEC1 is BHLH-B2 (412 aa); DEC2 (482 aa) is BHLH-B3. DEC1 and DEC2 are regulators of the mammalian molecular clock and show striking circadian oscillation in the suprachiasmatic nucleus. DEC2 inhibits transcription from the Per1 (See period) promoter induced by Clock/Bmal1.
2. Deleted in esophageal cancer 1 (70 aa), a candidate tumour suppressor.