Data normalized to samples’ actin levels showed that compared to the control PBS group, HIV-1 infection decreased the expression of claudin-5, ZO-1, and ZO-2, respectively, by 3.8-fold (Fig. 4d, P = 0.03), 6.7-fold (Fig. 4h, P = 0.0005) and 4.85-fold (Fig. 4l, P = 0.006). Here, CLDN5 is linked to HIV-1 infection.