TBR1 interacts with the forkhead transcription factors FOXP1 (OMIM *605515) and FOXP2 (OMIM *605317)18,20, both of which are implicated in neurodevelopmental disorders characterized by speech and language impairment, of differing severity and specificity (OMIM #613670 and #602081, respectively)21–23. This evidence concerns the gene TBR1 and neurodevelopmental disorder.