PAX6, also known as paired box protein 6, is a master regulator of eye development. It is essential for the correct patterning and formation of the multi-layered optic cup during eye development, and is involved in the developing lens and corneal epithelium. In adulthood, it is mostly expressed in cornea, iris, and lens. PAX6 is a dosage-sensitive gene, highly regulated by several elements. Its study through genetic models has been crucial for understanding its functions [3].

Aniridia, a pan-ocular genetic developmental eye disorder, is mainly caused by heterozygous PAX6 mutations. Over the past decades, several disease models, including mouse and zebrafish strains, and human-induced pluripotent stem cells (hiPSCs) from aniridia patients, have been investigated. These models help to understand the molecular pathophysiology of aniridia. For example, the study of PAX6-related models has shown that PAX6 is the master transcription factor of early eye development, and its deficiency can lead to aniridia-related phenotypes [1]. Also, PAX6 is involved in corneal epithelial homeostasis. The knockdown of PAX6 in limbal stem/progenitor cells affects the expression of downstream target WNK2, disrupting corneal differentiation and homeostasis [2].

In conclusion, PAX6 is of great importance in eye development and corneal epithelial homeostasis. The study of PAX6 through disease models, especially in aniridia, has deepened our understanding of its biological functions and the underlying molecular mechanisms, providing a basis for potential therapeutic strategies for related eye diseases.