Hnf4a, short for hepatocyte nuclear factor 4 alpha, encodes a transcription factor crucial for the development and function of the pancreas and liver [4]. It is involved in multiple biological processes such as regulating reabsorption-related genes during murine kidney development, influencing hepatocyte differentiation, and modulating glucocorticoid action in the liver [3,5,6]. Mutations in Hnf4a have been linked to Maturity Onset Diabetes of the Young (MODY), type 2 diabetes, and Fanconi syndrome [2,4,7].

In mouse models, repeated in vivo delivery of LNP-encapsulated Hnf4a mRNA robustly inhibited fibrogenesis in 4 independent mouse models of hepatotoxin-and cholestasis-induced liver fibrosis, suggesting its potential as a therapeutic target for liver fibrosis and cirrhosis [1]. In human kidney organoids, knockout of Hnf4a, but not Hnf4g, impaired reabsorption-related molecule expression and microvilli formation in human proximal tubules, revealing its role in proximal tubule differentiation [3].

In conclusion, Hnf4a plays essential roles in the development and function of multiple organs and is involved in various diseases like diabetes and liver fibrosis. The study of Hnf4a using gene-knockout models, such as in mouse models and human kidney organoids, has provided insights into its functions in specific biological processes and disease conditions, offering potential therapeutic directions for related diseases.