Transcription factor that binds to the E-box and functions as inhibitor of transcription. DNA binding requires dimerization with an E protein. Inhibits transcription activation by ASCL1/MASH1 by sequestering E proteins (By similarity). First detected in 6 to 9 hour old embryos. Expression is highest in 9 to 15 hour old embryos. First detected in stage 11 embryos within the neurogenic region. Detected in the procephalic region, the ventral nerve cord, subesophagal, thoracic and abdominal ganglia in stage 13 to 14 embryos. Detected in embryonic midgut primordia. Barely detectable at the first stage of larval development. Not detectable in older larvae, pupae or adults.