Heavy sialic acid modification on the termini of tumor-surface glycoproteins and glycolipids that project into the glycocalyx “canopy” (approximately 100–200 nm above the tumor-cell plasma membrane) represses cellular immunity via inhibitory Siglec 7 and 9 receptors on the CD8+ T cell (and NK cell) surface. The gene discussed is CD8A; the disease is neoplasm.