TBX19 is a T-box transcription factor that plays critical roles in pituitary development and corticotroph cell function. The protein serves as a transcriptional regulator involved in developmental processes, with the ability to activate POMC gene expression and repress alpha glycoprotein subunit and thyroid-stimulating hormone beta promoters 1. TBX19 is essential for corticotroph lineage specification in pituitary neuroendocrine tumors, where it defines the TPIT lineage distinct from other pituitary cell types 2 3. Mutations in TBX19 cause isolated ACTH deficiency (IAD), a rare autosomal recessive disorder characterized by severe early-onset adrenal failure due to inadequate ACTH production, while other pituitary hormones remain normal 4. Beyond its classical pituitary role, TBX19 appears to regulate cancer cell stemness and metabolism in various tumor types. In hepatocellular carcinoma, TBX19 promotes cancer stem cell properties and is negatively regulated by RIPPLY1 5 and MGRN1-mediated degradation 6. Additionally, chimeric transcripts involving TBX19 have been identified in prostate cancer, where they contribute to tumor progression through both protein-coding and long non-coding RNA mechanisms 7. The gene maps to chromosome 1-q24 and belongs to the T-box gene family involved in embryonic development 1.