Contributes to sequence-specific DNA binding activity. Involved in chaeta development; imaginal disc-derived appendage morphogenesis; and negative regulation of DNA-templated transcription. Part of protein-containing complex. Is expressed in several structures, including gut section; imaginal disc; organism subdivision; sense organ; and sensory nervous system primordium. Human ortholog(s) of this gene implicated in X-linked lissencephaly 2; X-linked recessive disease (multiple); corpus callosum agenesis-abnormal genitalia syndrome; and syndromic X-linked intellectual disability Hedera type. Orthologous to human ARX (aristaless related homeobox).