Jun, also known as c-Jun, is a basic leucine zipper (bZIP) transcription factor and a prototypic member of the activator protein-1 (AP-1) family. It can form homo-or heterodimers, bind to DNA, and regulate gene transcription. Jun is involved in numerous cell activities such as proliferation, apoptosis, survival, tumorigenesis, tissue morphogenesis, and also plays a role in the development of certain neurodevelopmental disorders [1,2,3]. It is regulated by extracellular signals that can induce post-translational modifications, altering its transcriptional activity [1].

In gene knockout mouse models, c-Jun has been shown to integrate signals of several developmental pathways, like EGFR-ERK, EGFR-RhoA-ROCK, and activin B-MAP3K1-JNK for embryonic eyelid closure [1]. This indicates its significance in coordinating complex developmental processes.

In conclusion, Jun is a multifunctional transcription factor involved in a wide range of biological functions, from cell-level activities to complex developmental processes. The study of Jun using gene knockout mouse models has provided valuable insights into its role in embryonic development, as well as its potential involvement in diseases such as cancer and autism spectrum disorder [1,2,3].