Moreover, plasma SIVsab Env variants in AGMs accumulated higher mutation frequencies within V1 (mutation frequency mean in AGM vs. RM variants, 5.4 vs. 0.22% at 22 or 18 wpi, and 6.7 vs. 3.5% at 1 ypi, respectively), and V2 loops (mutation frequency mean in AGM vs. RM variants, 1.8 vs. 0.086% at 22 or 18 wpi, and 5.9 vs. 3.2% at 1 ypi, respectively) compared to RM Env variants over the course of infection (Fig. 4b). This evidence concerns the gene ERVW-1 and infection.