FRAS1 is a basement membrane protein essential for embryonic epithelial-mesenchymal integrity and organogenesis 1. It localizes exclusively to epithelial basement membranes where it functions in the sublamina densa region 2. FRAS1 forms a mutually stabilized protein complex with FREM1 and FREM2 1, collectively regulating epidermal-basement membrane adhesion and preventing dermal-epidermal detachment 1. During brain development, FRAS1 is expressed in choroid plexuses and cortical, hippocampal, and amygdalar regions, contributing to brain organization and extracellular matrix structure 3. Mutations in FRAS1 cause Fraser syndrome, an autosomal recessive disorder characterized by cryptophthalmos, syndactyly, genitourinary abnormalities, and craniofacial dysmorphism 4. FRAS1 deficiency results in embryonic skin blistering, eyelid and digit fusion, and malformed lungs and kidneys 3. Additionally, FRAS1 mutations increase congenital diaphragmatic hernia susceptibility through impaired anterior mesothelial fold progression 5. Recently, FRAS1 emerged in cancer biology: in ovarian cancer, CRL4-DCAF13 ubiquitin ligase targets FRAS1 for degradation; FRAS1 promotes cell proliferation and migration via FAK signaling pathway activation 6. These findings reveal FRAS1's dual role in developmental morphogenesis and emerging oncogenic pathways.