Transcription factor (PubMed:30291162). Represses expression of genes involved in differentiation of touch receptor neurons (TRN), probably acting as a heterodimer with egl-44, perhaps by occupying similar cis-regulatory elements as an unc-86/mec-3 heterodimer (PubMed:30291162). Plays a role in cell fate specification of neurons, including the hook neuron HOB, the gas-sensing neuron BAG and touch receptor neurons (PubMed:12954713, PubMed:25395666, PubMed:30291162). Plays a role in neuron differentiation by repressing the expression of zag-1 in FLP neurons, probably acting as a heterodimer with egl-44; because zag-1 represses expression of egl-46 and egl-44, together these proteins form a bistable, negative-feedback loop that regulates the choice between neuronal fates (PubMed:30291162). Acts downstream of egl-44 to prevent touch cell differentiation in FLP neurons (PubMed:11274062). Involved in male mating behavior, acting in concert with egl-44, via modulation of expression of polycystins lov-1 and pkd-2, homeodomain protein ceh-26, and neuropeptide-like protein nlp-8 (PubMed:12954713). Modulates the expression of a subset of terminal differentiation genes involved in O(2)- and CO(2)-sensing, acting in parallel to ets-5 and egl-13 (PubMed:25395666). May act upstream of RFX transcription factor daf-19 to regulate gene expression specifically in the HOB neuron (PubMed:20923979). Plays a role in specifying commissural dendrites of the PVD nociceptive neurons, acting in concert with egl-44 (PubMed:29031632). In association with egl-44, regulates cell cycle exit in the neuronal Q cell lineage (PubMed:23946438). Interacts (via C-terminus) with egl-44 (via N-terminus); the interaction is direct; the interaction may regulate transcription. Localized to nucleus during interphase and evenly distributed in the cytoplasm of dividing Q.a and Q.p neuroblasts. Expressed in touch cells, HSN cells, ventral cord motor neurons and ciliated ray neurons. Expressed in neuronal cells, initially in embryos after gastrulation, including ventral cord motor neurons during the L1 larval stage, FLP, AVM and HSB neurons during L2, and PVM neurons during L3 (PubMed:11274062, PubMed:12954713). Expressed in the BAG neurons at the L2 and L3 stages of larval development (PubMed:25395666). Expressed in the HOB neuron beginning at the larval L4 stage and continuing throughout adulthood (PubMed:12954713). Expressed in the Q neuroblast lineage during larval development (PubMed:23946438, PubMed:11274062). Belongs to the INSM1 family.