FGF6 (fibroblast growth factor 6) is a conserved member of the FGF family that plays critical roles in muscle development and regeneration. The protein is expressed primarily in skeletal muscle, beginning at the myotomal stage and peaking in differentiated fetal muscle masses 1. FGF6 functions as a mitogenic factor that promotes cell proliferation while repressing terminal myoblast differentiation, and its action is mediated through FGFR4 receptor binding 1. The protein regulates multiple cellular processes including proliferation, differentiation, migration, angiogenesis, and myogenesis through activation of PI3K/AKT and MAPK signaling pathways 2. FGF6 contains a signal peptide essential for its transforming capacity and can be glycosylated when processed through the endoplasmic reticulum 3. In pathological contexts, FGF6 demonstrates tissue-protective effects, promoting cardiac repair after myocardial infarction by inhibiting the Hippo pathway and facilitating YAP nuclear translocation 4. Additionally, FGF6 participates in muscle-liver crosstalk during acute liver injury, regulating liver regeneration through the FGF6-FGFBP1 axis 5. However, FGF6 also exhibits oncogenic properties and is implicated in various cancers, though it may have tumor-suppressive effects in oral squamous cell carcinoma 6.