Required for larval development and for cell fate specification and migration of CAN neurons (PubMed:9475729, PubMed:2361334). Required for generation, or placement, and differentiation of the ALA neuron, and may play a role in ALA axon migration (PubMed:20501595). Expressed in several neurons including AIY, CEPDL, RID, ALA, RMED, AIN, AVJ and CAN neurons. RNAi-mediated knockdown causes severe defects in the ALA neuron in young adults, and when RNAi is begun embryonically, some individuals lack a detectable ALA neuron. Belongs to the paired homeobox family.