Ready-to-use ELISA kits are available for the detection of Le-PAS, an alias of the protein, neuronal PAS domain protein 4. The official gene symbol is NPAS4. The protein, with a mass of 87.1 kDa and length of 802 residues, is reported to be nuclear. It may be known by other names, including: NXF, Le-PAS, class E basic helix-loop-helix protein 79, PAS domain-containing protein 10, HLH-PAS transcription factor NXF, and neuronal PAS domain-containing protein 4, and bHLHe79.