Transcription factor that binds to the 5'-TGATNNAT(G/T)(G/A)-3' PBC/Hox lineage enhancer region of sem-2 to promote cell fate specification in the postembryonic mesoderm (also known as the M lineage) (PubMed:21307099). Required for the M lineage-specific expression of the transcription factor, mls-2 (PubMed:18316179). Required for asymmetric division of the T hypodermal cell, probably acting via the regulation of asymmetric expression of Meis protein psa-3 in concert with homeobox protein nob-1 and the Wnt-MAPK pathway (PubMed:16824957). Has a role in the mig-13 pathway to promote the guidance, migration and positioning of Q neuroblasts and their descendants along the anteroposterior body axis and the anterior migration of BDU interneurons (PubMed:15750187). Also required for normal vulval formation (PubMed:15750187). Plays a role in regulating gene expression in dopaminergic neurons, acting in midbody PDE neurons, and acting redundantly with ceh-40 in head neurons (PubMed:23788625). May activate dopamine pathway genes in concert with ETS domain-containing protein ast-1, and homeobox proteins ceh-43 and ceh-40 (PubMed:23788625). Interacts with Meis protein psa-3 (PubMed:16824957). Interacts with homeobox protein nob-1 (PubMed:16824957). Localized to the nucleus, in the T hypodermal cell, in a psa-3-dependent manner. Expressed in head dopaminergic neurons. Expressed in QR and QL neuroblasts, P and V cells and all their respective descendents, M cells, BDU interneurons, ALM and HSM neurons, body wall muscles, I4, all ventral cord neurons and in a few unidentified neurons in the head behind the posterior bulb of the pharynx during the L1 stage of larval development (PubMed:15750187). Expressed in V cell descendents from the larval stage of development to adulthood (PubMed:15750187). Expressed in the midbody dopaminergic PDE neurons throughout life (PubMed:23788625). RNAi-mediated knockdown results in egg laying defects, abnormal migration of QR neuroblast lineage cells and vulval protrusions due to ectopic induction and defective morphogenesis of vulval precursors cells (PubMed:15750187). RNAi-mediated knockdown results in the absence of the transcription factor, mls-2, in the M lineage (PubMed:18316179). Belongs to the TALE/PBX homeobox family.