PX-12 also affects oxidoreductase activity (Huber et al., 2008) and we therefor decided to test if PX-12 interferes with the early infection event by utilizing an infectivity assay consisting of TZM-bl (HeLa/CD4/CXCR4/CCR5) cells which contain a luciferase gene that is under the control of the HIV-1 promoter. This evidence concerns the gene CD4 and infection.