May be responsible for anchoring smooth muscle cells to elastic fibers, and may be involved not only in the formation of the elastic fiber, but also in the processes that regulate vessel assembly. Has cell adhesive capacity. Homotrimer associated through a moderately stable interaction of the C-terminal globular C1q domains, allowing the nucleation of the triple helix and then a further quaternary assembly to higher-order polymers via intermolecular disulfide bonds (By similarity). Interacts with EMILIN1. Found mainly at the interface between amorphous elastin and microfibrils. Highest levels are present in fetal heart and adult lung. Intermediate levels in peripheral leukocytes, placenta, and spinal cord and low expression in fetal brain, spleen, thymus, and lung and in adult heart, aorta, testis, bone marrow, small intestine, thymus, lymph node, and appendix.