Fibrillins are structural components of 10-12 nm extracellular calcium-binding microfibrils, which occur either in association with elastin or in elastin-free bundles. Fibrillin-containing microfibrils provide long-term force bearing structural support. Predominantly expressed in connective tissues such as skeletal muscle, tendon, skin, perichondrium and periosteum. Highly expressed in fetal lung, brain, kidney. Expressed at low level in prostate, testis, mammary gland, uterus, ovary, placenta, bladder, adrenal gland, thyroid, fetal thymus, fetal liver, liver, fetal heart and heart. Probably forms intermolecular disulfide bonds either with other FBN3 molecules or with other components of the microfibrils. Belongs to the fibrillin family. Extended N-terminus.