FBLN1 and neoplasm: In Kaposi’s sarcoma, an angioproliferative tumor of vascular endothelial cells, significant downregulation of fibulin-2 is demonstrated in combination with downregulated fibulin-3 and fibulin-5 and upregulation of fibulin-1, suggesting that loss of fibulin-2 compromises the structural integrity of vascular basement membrane due to loss of interactions between fibulin-2 and other ECM proteins, inducing uncontrolled cell proliferation, migration, and invasion [68].