Gli3, a member of the Glioma-associated oncogene homolog family, is a transcription factor in the Hedgehog (Hh/HH) signaling pathway [1]. It exists in full-length (Gli3-FL/GLI3-FL) and repressor (Gli3-R/GLI3-R) forms. In the Hh pathway, Gli3-FL targets the GLI1 promoter to regulate Hh genes when the pathway is activated, while in the absence of Hh signaling, Gli3-R represses Hh functions [1]. Gli3 is crucial for tissue development, immune cell development, and is associated with various diseases [1].

In mice, the absence of Gli3 impairs brain and lung development [1]. In muscle stem cells, GLI3 is required to maintain satellite cells in a G0 dormant state, and its depletion leads to satellite cells entering the GAlert state without injury, along with increased proliferation and self-renewal, suggesting GLI3 controls mTORC1 signaling to regulate muscle stem cell activation [2]. In Pallister-Hall syndrome (PHS), a truncating variant in the middle third of the GLI3 gene is associated with multiple clinical phenotypes, including congenital anomalies of the kidney and urinary tract (CAKUT) [3].

In conclusion, Gli3 is essential in the Hh signaling pathway, regulating tissue and immune cell development. Mouse models, such as Gli3 knockout models, have revealed its role in various biological processes and disease conditions like PHS. Understanding Gli3 helps in elucidating the mechanisms of development and disease, potentially providing insights for therapeutic strategies.