CD4 and infection: To address this constraint, several studies have been conducted to prevent infection by modifying CD4 CAR T cells with CCR5-targeting zinc finger nucleases [118, 119], deleting the CCR5 gene through gene editing techniques [120], or designing broadly neutralizing antibodies (bNAbs) that target different epitopes on the HIV envelope protein, including the CD4 binding site, outer proximal region of the glycoprotein 41 (gp41) membrane, and variable region glycans [121–124].