Probable transcription factor, involved in posterior embryonic patterning, morphogenetic movements of the posterior hypodermis, and cell fate specification (PubMed:10781051, PubMed:21408209). May regulate expression of transcription factor dmd-3 (PubMed:21408209). RNAi-mediated knockdown in adults has no effect on their F1 progeny, but increases the frequency of posterior morphological abnormalities on a homeobox nob-1 mutant background (PubMed:10781051). However, RNAi-mediated knockdown in L1 larvae causes defects in tail tip morphogenesis, which are exacerbated on a nob-1 mutant background (PubMed:21408209). Belongs to the abd-b homeobox family.