Neuronal PAS domain-containing protein 2, Neuronal PAS2, Basic-helix-loop-helix-PAS protein MOP4, Class E basic helix-loop-helix protein 9, bHLHe9, Member of PAS protein 4, PAS domain-containing protein 4, NPAS2, BHLHE9, MOP4, PASD4
BMAL1-NPAS2 heterodimers activate E-box element (5- CACGTG-3) transcription of a number of proteins of the circadian clock. This transcription is inhibited in a feedback loop by PER, and also by CRY proteins (By similarity).