Human FSTL1 ELISA kit for the quantitative detection of human follistatin-like 1 (FSTL1) in cell culture supernates, serum and plasma (heparin, EDTA).

FSTL1 (also known as FRP) is a protein that in humans is encoded by the FSTL1 gene. FSTL1 gene is mapped to chromosome 3q13.33 based on an alignment of FSTL1 sequence with the genomic sequence (GRCh37). This gene encodes a protein with similarity to follistatin, an activin-binding protein. It contains an FS module, a follistatin-like sequence containing 10 conserved cysteine residues. This gene product is thought to be an auto-antigen associated with rheumatoid arthritis. This gene may modulate the action of some growth factors on cell proliferation and differentiation. It was suggested that fibroblast-secreted FSTL1 acts on macrophages to increase TNF and IL1B production and IL6 activity.