Fibronectins bind cell surfaces and various compounds including collagen, fibrin, heparin, DNA, and actin (PubMed:3024962, PubMed:3900070, PubMed:3593230, PubMed:7989369). Fibronectins are involved in cell adhesion, cell motility, opsonization, wound healing, and maintenance of cell shape (PubMed:3024962, PubMed:3900070, PubMed:3593230, PubMed:7989369). Involved in osteoblast compaction through the fibronectin fibrillogenesis cell-mediated matrix assembly process, essential for osteoblast mineralization (By similarity). Participates in the regulation of type I collagen deposition by osteoblasts (By similarity). Acts as a ligand for the LILRB4 receptor, inhibiting FCGR1A/CD64-mediated monocyte activation (PubMed:34089617). Binds fibronectin and induces fibril formation. This fibronectin polymer, named superfibronectin, exhibits enhanced adhesive properties. Both anastellin and superfibronectin inhibit tumor growth, angiogenesis and metastasis. Anastellin activates p38 MAPK and inhibits lysophospholipid signaling. Mostly heterodimers or multimers of alternatively spliced variants, connected by 2 disulfide bonds near the carboxyl ends; to a lesser extent homodimers. Interacts with FBLN1, AMBP, TNR, LGALS3BP and COL13A1. Interacts with FBLN7 (By similarity). Interacts with COMP (PubMed:12225811). Interacts (via type III repeats 9-14) with TNFAIP6 (via CUB domain); this interaction enhances fibronectin fibril assembly. TNFAIP6 may act as a bridging molecule between FN1 and THBS1 (PubMed:18042364). Interacts with TNR; the interaction inhibits cell adhesion and neurite outgrowth (By similarity). Interacts with FST3 and MYOC. (Microbial infection) Interacts with S.aureus FnbA. (Microbial infection) Interacts with M.bovis FbpB via the collagen-binding region. (Microbial infection) Interacts with recombinant S.pneumoniae PavA (rqcH). (Microbial infection) Interacts with recombinant S.suis FbpS (rqcH) via fibronectin's N-terminal 30 kDa region. (Microbial infection) Interacts with fibronectin-binding proteins from other Mycobacteria. A number of isoforms are produced. The diversity of isoforms depends on the V region and either of the two extra domains which can be either included or excluded (partially or completely for the V region). Expressed in the inner limiting membrane and around blood vessels in the retina (at protein level) (PubMed:29777959). Plasma FN (soluble dimeric form) is secreted by hepatocytes. Cellular FN (dimeric or cross-linked multimeric forms), made by fibroblasts, epithelial and other cell types, is deposited as fibrils in the extracellular matrix. Ugl-Y1, Ugl-Y2 and Ugl-Y3 are found in urine (PubMed:17614963). Expressed between 12 and 19 weeks post-conception (WPC) in Bruch's membrane, with expression in the choroid evident from 14 WPC onwards (at protein level) (PubMed:29777959). Expressed in the inner limiting membrane at 17 WPC (at protein level) (PubMed:29777959). Ugl-Y1, Ugl-Y2 and Ugl-Y3 are present in the urine from 0 to 17 years of age (PubMed:17614963, PubMed:3584091). Sulfated. It is not known whether both or only one of Thr-2155 and Thr-2156 are/is glycosylated. Forms covalent cross-links mediated by a transglutaminase, such as F13A or TGM2, between a glutamine and the epsilon-amino group of a lysine residue, forming homopolymers and heteropolymers (e.g. fibrinogen-fibronectin, collagen-fibronectin heteropolymers). Phosphorylated by FAM20C in the extracellular medium. Proteolytic processing produces the C-terminal NC1 peptide, anastellin. Some lysine residues are oxidized to allysine by LOXL3, promoting fibronectin activation and matrix formation. Serotonylated on Gln residues by TGM2 in response to hypoxia. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. Expressed by fetal and tumor-associated cells. Extended N-terminus. Extended N-terminus. Extended N-terminus. Extended N-terminus. Extended N-terminus. Extended N-terminus. Extended N-terminus. Fibronectin entry