PITX3 is a transcriptional regulator with dual roles in midbrain dopaminergic (mdDA) neuron development and lens morphogenesis. In dopaminergic neurons, PITX3 is essential for differentiation and long-term survival of substantia nigra neurons 1. It functions by reducing NCOR2/SMRT corepressor interaction with NR4A2/NURR1, thereby derepressing transcription of dopaminergic genes including TH, SLC6A3, and DRD2 2. In lens development, PITX3 maintains epithelial cell proliferation by positively regulating FOXE3 and negatively regulating PROX1, preventing premature cell cycle exit 3. Clinically, PITX3 mutations cause anterior segment dysgenesis and multiple forms of congenital cataracts, with 19 causal variants identified to date 4. While PITX3 polymorphisms show weak associations with early-onset Parkinson's disease in specific populations 5, meta-analyses indicate these variants are not major PD determinants 6. Additionally, PITX3 variants near 10q24.32 show genetic overlap with autism spectrum disorder and schizophrenia 7. Enhanced PITX3 expression in optimized dopamine differentiation protocols improves neuronal yield and functional properties for regenerative medicine applications 8.