Adhesive glycoprotein that mediates cell-to-cell and cell-to-matrix interactions and may be involved in various processes including cellular proliferation, migration, adhesion and attachment. May play a role in ER stress response (By similarity). Homotrimer; disulfide-linked. Expressed both maternally and zygotically. Present at the gastrulation and post-segmentation stages. Belongs to the thrombospondin family.