The potential role of Mtv Sag in arthritis development is underscored by our findings that ERV reverse transcriptase inhibitors (such as Truvada) significantly mitigated SKG arthritis, probably by disrupting the effect of ERVs on innate and adaptive immune responses (67, 75, 76) and possibly influencing Sag-reactive T cell activation. This evidence concerns the gene SAG and arthritic joint disease.