GPC4 and cancer: For example, annexin A11, a phospholipid-binding protein, regulates exocytosis and cytokinesis (42); CD44v6 is a CD44 splicing isoform frequently associated with tumor progression (43); CD14 is a monocyte-associated surface protein, which was recently shown to be expressed in cancer cells and to regulate the tumor microenvironment (44); VGLUT2 is a glutamate transporter; and GPC4 is a cell surface sulfate proteoglycan that regulates insulin and WNT pathways (45, 46).