Sequence-specific transcription factor (By similarity). Regulates multiple developmental processes including brainstem, inner and outer ear, abducens nerve and cardiovascular development and morphogenesis as well as cognition and behavior (PubMed:16155570). Also part of a developmental regulatory system that provides cells with specific positional identities on the anterior-posterior axis. Acts on the anterior body structures. Seems to act in the maintenance and/or generation of hindbrain segments (By similarity). Activates transcription in the presence of PBX1A and PKNOX1 (By similarity). Interacts with OGT (via TPR repeats domain); the interaction takes place mainly in the nucleus (By similarity). Forms a DNA-binding heterodimer with transcription factor PBX1 (PubMed:9191052). The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. Lacks the homeobox domain. Lacks the homeobox domain. Belongs to the Antp homeobox family. Labial subfamily.