The class IV POU homeodomain transcription factor (POU-IV or Brn3) controls the differentiation of distinct neural cell types in Bilateria and its sister group Cnidaria, indicative of an evolutionarily ancient role for POU-IV in neural differentiation. In the cnidarian Nematostella vectensis, we and others have found that POU-IV regulates the maturation of mechanosensory cell types, namely, hair cells and stinging cells known as cnidocytes. However, the mechanism by which POU-IV orchestrates the maturation of two distinct mechanosensory cell types is not known. To bridge this knowledge gap, we are studying the identity and function of downstream target genes of POU-IV. By using ChIP-Seq and RNA-seq, we find that a number of effector genes such as ion channel-encoding genes are directly activated by POU-IV, while several transcription factor-encoding genes, including a cnidocyte differentiation gene PaxA, are directly repressed by POU-IV. Regarding which downstream target genes of POU-IV are involved in the maturation of hair cells, cnidocytes, or both are currently being investigated.