NDV, mumps, and SeV use sialic acid–containing sialoglycoproteins as the cell surface receptors.49,50 The abundant presence of sialoglycoproteins on the surface of cancer cells13,51 most likely promotes preferential association of the virus with malignant rather than with normal cells and contributes to their selective cytolytic effect in primary tumors and in metastases. The gene discussed is CD177; the disease is cancer.