Nef effect on CXCR4 was recapitulated in T cell lines and monocytes transduced with bacterially expressed hexa-His-tagged myristoylated Nef containing TAT-Arginine-rich motifs (RRMs) (Figure S1 A) and in single cycle infection of CEM cells with VSV-G pseudotyped Nef (+) and Nef (−) HIV (Figure S1 B). This evidence concerns the gene S100B and infection.