CYP24A1 and HIV-1 infection: Subsequently, we evaluated the combination of the gp41-targeting HIV-1 fusion inhibitor IBP-CP24 and the gp120-targeting bNAb N6 at a molar ratio of 6: 1 (starting concentration of IBP-CP24 and N6 is 171.5 nM and 28.5 nM, respectively) based on their IC50 values for potential synergism against HIV-1 infection.