CD47 and astrocytoma (excluding glioblastoma): The cytoplasmic protein PLIC-1 binds directly to the C-terminal cytoplasmic tail of CD47 isoforms 2 and 4, thereby promoting cell spreading, altering intermediate filament distribution (13), recruiting heterotrimeric G proteins to CD47 (61, 62), inhibiting chemotaxis signaled by the Gi-coupled receptor CXCR4 (62), activating the PI3K/Akt pathway in astrocytoma cells (63), and regulating cAMP signaling by CD47.