CD4 and HIV infectious disease: Two other in vitro assays demonstrated that MSX-122 exhibits a different profile than AMD3100 and other reported anti-CXCR4 compounds: (1) MSX-122 did not inhibit T-tropic HIV infection (via the formation of the CXCR4/CD4/GP120 complex), while AMD3100 did [17]; and (2) unlike AMD3100, MSX-122 proved to be inactive in our calcium flux assay.