Endogenous retrovirus group FRD member 1, envelope (ERVFRD-1)

"Endogenous retrovirus group FRD member 1, envelope" (ERVFRD-1), commonly called **Syncytin-2**, is a gene derived from an ancient retrovirus that has been stably integrated into the primate genome for roughly 45 million years[3][4][6]. This gene encodes a retroviral envelope glycoprotein that is **fused into human biological processes**: its protein product mediates the **fusion of placental trophoblasts**, forming the syncytiotrophoblast layer critical for placenta development in mammals[1][3][4][6]. Syncytin-2 is specifically expressed in the placenta, where it interacts with its receptor, **MFSD2A**, to promote cell-cell fusion and placental morphogenesis[1][3][4]. While most endogenous retroviral genes are non-functional, Syncytin-2 has been conserved for its **essential role in human reproduction**[1][3][4][6]. Recent studies suggest ERVFRD-1/Syncytin-2 may have *additional significance* in cancer biology, as its expression pattern is associated with tumor immunoregulation and prognosis in some cancers such as kidney renal clear cell carcinoma[5]. \n**Is it a therapeutic target?** \n**No**, ERVFRD-1/Syncytin-2 is not recognized as a therapeutic drug target such as a receptor, enzyme, or transporter in standard pharmacological or clinical contexts. It is *not* directly targeted by drugs, nor does it act as a classical receptor or enzyme[1][3][4][5][6].\n\n**Is something wrong with this target?** \n**Yes**, there is an issue in the query context: \n- The "pseudogene" reference in ENSG00000275959 is potentially misleading. While some annotations describe pseudogene features, the functional locus (ERVFRD-1, Syncytin-2) is an **active gene with a well-established role in placental fusion** rather than a nonfunctional pseudogene[1][3][4][6]. \n- **Syncytin-2/ERVFRD-1** is a *fusogenic envelope protein* with essential physiological function, not commonly a drug or receptor target.\n\n**Summary:** \nEndogenous retrovirus group FRD member 1, envelope (Syncytin-2, ERVFRD-1) is an **endogenous retroviral protein** with an essential role in human placental development, rather than a therapeutic drug target. It is not considered a classic pharmacological target and is sometimes inaccurately referred to as a "pseudogene" despite its clear expression and function in humans. Its major role is fusogenic, facilitating cell-cell fusion in trophoblasts during placentation. There are no known drugs targeting this protein, but its expression has potential value as a *biomarker* in some cancers[5].

Other names

Syncytin-2HERV-FRD provirus ancestral Env polyproteinLOC100533736Endogenous retrovirus group FRD, member 1 pseudogeneSyncytin-2 precursor

Not recognized as a therapeutic drug target; mechanism is endogenous cell–cell fusion in placenta[1][3][4][6]