We employed probes residues 421–433 or 416–433 containing electrophilic phosphonate groups (E-421–433 and 416–433, respectively), to identify antibodies that neutralize primary HIV strains, including antibodies produced spontaneously by humans without HIV infection (Planque et al., 2007), patients with prolonged HIV infection (Planque et al., 2010) and animals immunized with E-gp120 (Nishiyama et al., 2009). This evidence concerns the gene ITIH4 and HIV infectious disease.