Vital for embryonic development and essential for the proper function of the excretory cell (PubMed:11171402). Required for the transdifferentiation of the Y rectal epithelial cell to the PDA motor neuron during larval development (PubMed:22493276). Interacts with egl-27, sox-2 and sem-4 (PubMed:22493276). Interacts with wdr-5.1 (PubMed:25124442). Expressed in a series of neurons in the ring ganglia, excretory cell, dividing neuroblasts in the ventral cord and rectal cells. RNAi-mediated knockdown results in defective PDA motor neuron differentiation as a result of failed Y rectal cell migration from the rectum. Belongs to the POU transcription factor family. Class-3 subfamily.