Transcription factor specifically required for the formation of motile cilia (PubMed:9096351, PubMed:9739041, PubMed:10873152, PubMed:14996907, PubMed:22357932, PubMed:27965440). Acts by activating transcription of genes that mediate assembly of motile cilia, such as CFAP157 (PubMed:27965440). Binds the DNA consensus sequences 5'-HWDTGTTTGTTTA-3' or 5'-KTTTGTTGTTKTW-3' (where H is not G, W is A or T, D is not C, and K is G or T) (PubMed:9096351). Activates the transcription of a variety of ciliary proteins in the developing brain and lung (PubMed:28666954, PubMed:27914912). Predominantly expressed in tissues containing motile cilia. Expressed in the developing fetal lung epithelium and developing brain (at protein level). Mice lack motile respiratory tract cilia and exhibit randomization of the left-right body axis due to loss of motile cilia in the embryonic node (PubMed:9739041, PubMed:10873152). Motile type cilia with a '9 + 2' microtubule ultrastructure are absent in epithelial cells, including those in the airways (PubMed:10873152). Belongs to the FOXJ1 family.