Probable transcription factor (PubMed:28056346). Involved in motor neuron fate determination and maintenance, acting as a transcriptional repressor to counteract gene activation by transcription factor unc-3 in a subset of motor neurons (PubMed:28056346). Required throughout development to repress transcription by unc-3, probably acting by binding to specific promoter elements (PubMed:28056346). Represses expression of DA and DB motor neuron-specific effector genes, such as unc-129 and unc-53, in VA and VB motor neurons (PubMed:28056346). Expressed in the VA and VB motor neurons and at lower levels in the SABV neuron pair. Expression begins around the postembryonic birth of VA and VB motor neurons at the late first larval L1 stage, and is maintained throughout the life of the animals.