MFAP1 was first named for proteins associated with microfibrils which are an important component of the extracellular matrix (ECM) of many tissues. For example, MFAP1 has been shown to be associated with elastin-like fibers at the base of Schlemm's canal endothelium cells, in the juxtacanalicular tissue, and in the uveal region. Based on its role in the ECM and the proximity of the MFAP1 gene to FBN1 it was hypothesized that mutations in MFAP1 contributed to heritable diseases affecting microfibrils, Marfan syndrome but this has now been shown not to be the case. MFAP1 has also been shown to interact directly with certain pre-mRNA processing factor proteins, Prps, which are also spliceosome components and is thus required for pre-mRNA processing. MAFP1 bound to Pr38 of yeast is necessary for cells in vivo to progress from G2 to M phase.