Bhlhe40 - basic helix-loop-helix family, member e40

This gene encodes a basic helix-loop-helix protein expressed in various tissues. The encoded protein can interact with Arntl or compete for E-box binding sites in the promoter of Per1 and repress Clock/Arntl's transactivation of Per1. This gene is believed to be involved in the control of circadian rhythm and cell differentiation. [provided by RefSeq, Feb 2014]