Involved in pre-mRNA splicing as a component of the spliceosome. Component of the spliceosome B complex. Interacts with PRPF38A (via N-terminal interaction domain). Widely expressed. Belongs to the MFAP1 family. Was initially identified as a component of the elastin-associated microfibrils (PubMed:1374398). More recent results indicate it is instead part of the spliceosome B complex.