Early growth response protein 3 is a transcriptional regulator that belongs to the EGR family of C2H2-type zinc-finger proteins. It is an immediate-early growth response gene which is induced by mitogenic stimulation. The protein encoded by this gene participates in the transcriptional regulation of genes in controlling biological rhythm. It may also plays a role in muscle development.The human EGR3 gene was described by Patwardhan et al. (1991) as predicting a 387-amino acid protein containing 3 C2H2 zinc fingers nearly identical to those of EGR1 and EGR2. The gene was known to be induced in various brain regions in response to stress or following focal brain injury. Morris et al. (1998) stated that, in the SCN, it probably participates in the transcriptional regulation of genes in response to retinal input, as had been proposed for FOS.