May function as a positive regulator of transcription in developing and differentiated neurons, regulating common aspects of neuronal differentiation and maintenance. Requirement in the CNS may be higher than in the peripheral system. Vital for development of the indirect flight muscles. Homodimer. Binds DNA as a dimer (By similarity). Not in nucleolus. Additional isoforms seem to exist. Isoform A is highly expressed in possibly all embryonic neurons and is enriched in adult heads. Other isoforms show similar expression at a much lower level. Transient expression in migrating myoblasts. Expressed throughout development, beginning at embryonic stage 12 when levels steadily increase and then drop dramatically at third-instar larvae. Levels increase in 24 hour pupae and remain until adulthood. Belongs to the NRF1/Ewg family. Unusual initiator. The initiator methionine is coded by a non-canonical CTG leucine codon.