Another mechanism that might account for differences in the sensitivity of cell lines toward infection by Syn-1-pseudotyped viruses in the presence of Gal-1 might rely on the variation in the abundance of other cell surface proteins of glycolipids inducing cell signaling following binding to Gal-1, although this is less likely, as it should have similarly impacted Syn-2-pseudotyped virus infection. This evidence concerns the gene SYN2 and infection.