Follistatin-like protein 4 (FSTL4)

Follistatin-like protein 4 (FSTL4) is a secreted glycoprotein encoded by the FSTL4 gene on chromosome 5q31.1, consisting of 16 exons[1]. It is a member of the SPARC family of proteins, structurally related to other follistatin-like proteins, with one follistatin module, a Kazal-like domain, EF-hand domain(s), and immunoglobulin-like features that enable diverse interactions in the extracellular space[1]. FSTL4 is predicted to bind brain-derived neurotrophic factor and calcium ions, and to regulate biological processes such as differentiation and BMP signaling[4]. The protein is found in the extracellular compartment, particularly in areas of the central nervous system, and may participate in cell signaling and intercellular interactions linked to development and disease[1][4]. Data suggest potential involvement in the progression of cancer, notably in neoplastic transformation and metastasis, but the protein’s full biological and clinical significance requires further research[1][4]. No drugs, mechanism of action, biomarkers, or safety concerns have been reported in the literature relating to FSTL4 specifically as of mid-2025[1][4].

Other names

Follistatin-related protein 4FSTL4KIAA1061Follistatin-like protein 4follistatin-related protein 4