SHISA2 (shisa family member 2) is an endoplasmic reticulum-localized protein that serves as a negative regulator of both WNT and FGF signaling pathways through modulation of receptor maturation and surface presentation 12. The protein functions by inhibiting glycosylation and cell surface presentation of receptors like Frizzled3, thereby controlling pathway activation 1. SHISA2 plays crucial roles in multiple developmental processes, including muscle development where it regulates myoblast fusion through Rac1/Cdc42-mediated cytoskeletal remodeling 3. In neural development, Sonic Hedgehog signaling downregulates SHISA2 levels to enable proper commissural axon guidance and anterior turning after midline crossing 1. Disease relevance includes involvement in cancer progression, where overexpression promotes cell growth and invasion in human cancer cell lines 2, and association with stress-induced behavioral phenotypes through epigenetic repression in prefrontal cortex circuits 4. SHISA2 expression levels also correlate with prognosis in pancreatic cancer patients and serve as a biomarker in nasopharyngeal carcinoma 56. The protein's regulatory role in multiple signaling pathways makes it clinically significant for understanding developmental disorders, muscle diseases, and cancer progression.