TF isoforms. flTF is a 263–amino acid polypeptide that is divided into 3 domains: an extracellular domain, a transmembrane domain, and a cytoplasmic domain. The extracellular domain is composed of 2 fibronectin type 2–like domains. There are 3 N-linked glycosylation sites (N) and 2 disulfide bonds (S-S) in the extracellular domain. asTF contains the first 167 amino acids of TF spliced to 38 different amino acids at the C-terminus. The extracellular domain without the transmembrane domain is a soluble protein (sTF). Professional illustration by Patrick Lane, ScEYEnce Studios.