CXCR4 and neuroblastoma: Furthermore, HIV-1 surface protein, gp120, promoted Aβ secretion in primary embryonic rat hippocampal neurons (Aksenov et al., 2010), inhibited apoptosis of infected human neuroblastoma cells via inhibition of the Fas-pathway (Thomas et al., 2009), and induced neurotoxicity in human neuroblastoma cells through the CXCR4 and CCR5 chemokine receptors (Catani et al., 2000; Bardi et al., 2006).