CD4+ T cell depletion and viral replication of wt and Δ nef HIV-1 in tonsils from 35 experiments. (A, B) CD4+ T cell depletion (A) and p24 production (B). Each data point represents the mean value of quadruplicate parallel infections. p-values indicate statistical significance by Mann-Whitney-U analysis. (C, D) Boxplot presentation of the data shown in A and B. Boxes indicate the upper and lower quartile (box borders), median (line within the box) and the maxima and minima of each data set (vertical lines).