Transcription factor required for normal development of thymus, parathyroid glands, ultimobranchial bodies, teeth, skeletal elements of skull and larynx as well as distal limbs. {ECO:0000250, ECO:0000269|PubMed:12657635}. This is the function of PAX9 (paired box 9, Ensembl gene identifier ENSG00000198807).