Plays a crucial role in elastic fiber formation in tissue, and in the formation of ultrastructural connections between elastic laminae and smooth muscle cells in the aorta, therefore participates in terminal differentiation and maturation of smooth muscle cell (SMC) and in the mechanical properties and wall integrity maintenance of the aorta (PubMed:16478991, PubMed:19855011, PubMed:20019329, PubMed:26486174, PubMed:26711913, PubMed:28508064). In addition, is involved in the control of collagen fibril assembly in tissue throught proteolytic activation of LOX leading to cross- linking of collagen and elastin (PubMed:26690653, PubMed:26711913, PubMed:26220971, PubMed:26178373). Also promotes ELN coacervation and participates in the deposition of ELN coacervates on to microfibrils but also regulates ELN cross- linking through LOX interaction (PubMed:17324935). Moreover adheres to the cells through heparin binding in a calcium-dependent manner and regulates vascularlar smooth muscle cells proliferation through angiotensin signaling (PubMed:23636094). Homodimer; disulfide-linked (By similarity). Multimer; allows heparin binding (By similarity). Monomer (PubMed:17324935). Binds preferentially to p53 mutants (PubMed:10380882). Interacts with FBN1 (via N-terminal domain); this interaction inhibits EFEMP2 binding to LOX and ELN (By similarity). Interacts with ELN with moderate affinity; this interaction regulates ELN self-assembly maturation stage (PubMed:16478991, PubMed:17324935). Interacts with PCOLCE (PubMed:26220971). Interacts with collagen type IV trimer (COL4A1-COL4A1-COL4A2), NID2 and moderately with COL15A1-derived endostatin (PubMed:17324935). Interacts with EMILIN1; this interaction promotes the incorporation of EFEMP2 into the extracellular matrix (PubMed:28717224). Interacts with LTBP4; the LTBP4 long form (LTBP4L) has a stronger binding affinity than the LTBP4 short form and the LTBP4 long form promotes fibrillar deposition of EFEMP2 (PubMed:25713297). Interacts with LOX (via propeptide); this interaction is strong and facilitates formation of ternary complexes with ELN during elastic fiber assembly; this interaction limits interaction of EFEMP2 with FBLN5 (By similarity). Interacts with PITX2 (By similarity). Interacts with FBLN5 with moderate affinity (By similarity). Interacts with LOXL1 (via propeptide), LTBP1 and TGFB1 stronger than with LOXL2 and LTBP3 (By similarity). Localizes on the microfibrils surrounding ELN cores. Expressed in elastic fibers of the skin, near the dermal-epidermal junction, surrounding the hair follicles and throughout the dermis (PubMed:26178373). Expressed in tendon around tenocytes (PubMed:26711913). Prominently expressed in cartilage, bone, perichondrium and ligaments. Also detected in bone marrow stroma (PubMed:26690653). Expressed in aorta, lung, and esophagus (PubMed:17324935). At E(15), found in the perichondrium of the developing bone. At E(14) detected in the lung parenchyma. N-glycosylated; contains mostly complex-type glycans. Not O-glycosylated. Cleaved by ELANE; produces a 50-55 kDa fragment. Cleaved by MMP2 and MMP9; produces several fragments. Homozygous mice for the EFEMP2 gene appear to be outwardly normal (PubMed:16478991, PubMed:28508064). Homozygous mice exhibit severe lung and vascular defects including emphysema, artery tortuosity, irregularity, aneurysm, rupture, and resulting hemorrhages (PubMed:16478991, PubMed:19855011, PubMed:26178373, PubMed:28508064). Mice died perinatally (PubMed:16478991, PubMed:19855011). Mice with conditional knockout of EFEMP2, in vascular smooth muscle, grow normally, are fertile and exhibit an arterial stiffness (PubMed:19855011). Mice with conditional knockout of EFEMP2, in endothelial cell (EC) are healthy with an normal aorta (PubMed:20019329). Mice with conditional knockout of EFEMP2, in smooth muscle cells, die spontaneously at approximately 2 months of age despite absence of embryonic or neonatal lethality. Aortae exhibit large aneurysms exclusively in the ascending aorta. Aneurysms are observed with complete penetrance (PubMed:20019329, PubMed:26486174, PubMed:23636094, PubMed:26220971). Homozygous mice for the EFEMP2 gene die within 1-2 days after birth. Embryos at 19 dpc show bilateral forelimb contractures (PubMed:26711913, PubMed:26690653). Newborn homozygous mice demonstrate normal morphology of the skeleton (PubMed:26690653). Aneurysm may be prevent with postnatal administration of ACE inhibitor and/or angiotensin II receptor blocker (ARB). Belongs to the fibulin family.