Transcriptional repressor that may play a role in the specification and differentiation of lung epithelium. May also play a role in developing neural, gastrointestinal and cardiovascular tissues. Can act with CTBP1 to synergistically repress transcription but CTPBP1 is not essential. Plays a role in synapse formation by regulating SRPX2 levels. Involved in neural mechanisms mediating the development of speech and language. Forms homodimers and heterodimers with FOXP1 and FOXP4. Dimerization is required for DNA-binding. Interacts with CTBP1 (By similarity). Interacts with FOXP1 (PubMed:26647308). Isoform 1 and isoform 3 interact with TBR1 (PubMed:25232744, PubMed:30250039). Interacts with ZMYM2 (PubMed:32891193). Isoform 1 and isoform 6 are expressed in adult and fetal brain, caudate nucleus and lung. Expressed in the brain at 15 and 22 weeks of gestation, with a pattern of strong cortical, basal ganglia, thalamic and cerebellar expression. Highly expressed in the head and tail of nucleus caudatus and putamen. Restricted expression within the globus pallidus, with high levels in the pars interna, which provides the principal source of output from the basal ganglia to the nucleus centrum medianum thalami (CM) and the major motor relay nuclei of the thalamus. In the thalamus, present in the CM and nucleus medialis dorsalis thalami. Lower levels are observed in the nuclei anterior thalami, dorsal and ventral, and the nucleus parafascicularis thalami. Expressed in the ventrobasal complex comprising the nucleus ventralis posterior lateralis/medialis. The ventral tier of the thalamus exhibits strong expression, including nuclei ventralis anterior, lateralis and posterior lateralis pars oralis. Also expressed in the nucleus subthalamicus bilaterally and in the nucleus ruber. The leucine-zipper is required for dimerization and transcriptional repression. The disease is caused by variants affecting the gene represented in this entry. A chromosomal aberration involving FOXP2 is a cause of severe speech and language impairment. Translocation t(5;7)(q22;q31.2). Talking heads - Issue 51 of October 2004 FOXP2 entry