In a three-hour infection assay, we observed a significant reduction of EHV-1, which binds to α4β1 integrins, as well as EHV-1 gH4 or EHV-1 gHS440A (these two viruses cannot bind to α4β1-integrin) infections after treatment of cells with Rac1 and Cdc42 inhibitors. This evidence concerns the gene CDC42 and infection.