Es 3B and S3). We decided to use this cell line because of a smaller ratio between HIV transcripts and *mRNA in these cells compared to those in J-Lat 9.2 cells (Figure 2D, bars 3 and 4). The ratio between LTRand Rev-containing transcripts increased with the decreased levels of viral expression consistent with the rational equation (see Supplemental text 2), and revealed that the upstream transcri