ACTA1 and neoplasm: CD34 is a transmembrane sialomucin and adhesion molecule that plays a critical role in leukocyte transmigration and thus marks sites of potential leukocyte infiltration into tumors; αSMA is an actin isoform that marks contractile pericytes; and LYVE-1 is a hyaluronan binding receptor implicated in docking and transmigration of dendritic cells and tumor cells.