PAX6, also known as paired box protein 6, is a master regulator of eye development [2,3,5,6,7]. 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 mainly expressed in the cornea, iris, and lens [5]. PAX6 is a dosage-sensitive gene, highly regulated by multiple elements, and mutations in it can lead to various ocular and systemic abnormalities [5]. Genetic models, such as mouse and zebrafish strains and human-induced pluripotent stem cells, have been crucial in studying PAX6 [1].

In aniridia, a pan-ocular genetic developmental eye disorder, the vast majority of patients have heterozygous mutations in the PAX6 gene [1]. Research on mouse and zebrafish models, as well as human-induced pluripotent stem cells derived from aniridia patients, has provided insights into the molecular pathophysiology of aniridia [1]. In corneal epithelial cells, PAX6 is a master transcription factor determining cell fate, and its downstream target WNK2 is essential for corneal epithelial cell differentiation and maintaining corneal homeostasis [4].

In conclusion, PAX6 is of utmost importance in eye development and maintaining corneal epithelial homeostasis. Studies using various genetic models, especially those related to aniridia, have significantly advanced our understanding of how PAX6 functions and its role in disease. This knowledge can potentially lead to the development of new therapeutic strategies for PAX6-related eye disorders.