One or both of the "extra" type III modules (EIIIA and EIIIB) may be present in cellular fibronectin, but they are never present in plasma fibronectin.
Jedan ili oba "ekstra" tipa III modula (EIIIA i EIIIB) mogu biti prisutna u ćelijskom fibronektinu, ali oni nisu nikad prisutni u fibronektinu iz krvne plazme.