Viral gag mRNAs were quantified by real-time RT-PCR from RNAs extracted from lung tissues of SHIV-infected macaques with (RHU5, RMT5, 49P1, 52C, 52D, PJX, 57W, and PWJ) and without (RHT5, ROQ5, RJV5, and PHP) pneumonia. Briefly, total RNA was extracted from flash-frozen tissues, the samples were treated with DNase, and real-time RT-PCR was performed using 100 ng RNA for both, the cellular GAPDH transcript and viral gag-containing mRNA. The gag mRNA copy number was normalized to the GAPDH copy number to present the data from equivalent cell numbers.