FCN1

FCN1, or **Fibronectin type I domain-containing 1**, is a protein-encoding gene located on the short arm of chromosome 1 (1p36.11) in humans. It belongs to the fibronectin family, which are extracellular matrix proteins involved in cell adhesion, migration, and signaling. FCN1 is primarily expressed in the liver and plays a role in the innate immune response.

The FCN1 protein, also known as **fibronectin type I domain-containing protein 1**, is a soluble factor that contributes to complement activation, particularly through the lectin pathway. It binds to mannose-binding lectin (MBL) and activates the complement system, facilitating opsonization and clearance of pathogens. This interaction is critical for early immune defense against microbial infections.

Studies suggest that FCN1 may also influence inflammation and tissue repair. Its expression can be upregulated in response to infection or injury, indicating a regulatory role in immune modulation. Variations in FCN1 have been associated with susceptibility to certain infections and autoimmune diseases, though research in this area remains ongoing.

In addition to its immune functions, FCN1 has been implicated in cancer biology. Some studies propose that altered FCN1 expression may contribute to tumor progression or metastasis, though its exact role varies depending on the cancer type and context. Further investigation is needed to clarify its precise mechanisms in disease pathogenesis.

FCN1 is conserved across species, with homologs found in mice and other mammals, indicating its evolutionary importance. Research into FCN1 continues to explore its potential as a therapeutic target for infectious diseases, autoimmune conditions, and cancer.