T-box transcription factor TBX19 is a protein that in humans is encoded by the TBX19gene.
This gene is a member of a phylogenetically conserved family of genes that share a common DNA-binding domain, the T-box. T-box genes encode transcription factors involved in the regulation of developmental processes. This gene is the human ortholog of mouse Tbx19/Tpit gene. Studies in mouse show that Tpit protein is present only in the two pituitary pro-opiomelanocortin (POMC)-expressing lineages, the corticotrophs and melanotrophs.
The Tpit gene is responsible for a neonatal form of acth deficiency and hypocortisolism. 
Mutations in the human ortholog were found in patients with isolated deficiency of pituitary POMC-derived ACTH, suggesting an essential role for this gene in differentiation of the pituitary POMC lineage.
^Yi CH, Terrett JA, Li QY, Ellington K, Packham EA, Armstrong-Buisseret L, McClure P, Slingsby T, Brook JD (Mar 1999). "Identification, mapping, and phylogenomic analysis of four new human members of the T-box gene family: EOMES, TBX6, TBX18, and TBX19". Genomics55 (1): 10–20. doi:10.1006/geno.1998.5632. PMID9888994.