The gene is associated with producing new mitochondria as well as reducing oxidation damage and inflammation. Original article here, digests here and here.
Next, I'd be interested to see what the tissue expression profile is, particularly with respect to slow- and fast-twitch muscle fibers; a glance at the mouse transcriptome shows high expression in cardiac myocytes and smooth muscle, and a peak in thyroid, but not so much in skeletal muscle. It would also be interested to look into the geographic patterning among humans (if any); this is likely to be a fairly homogeneous sample in the context of overall human genetic diversity since it's an Israeli study that used Ashkenazi and non-Ashkenazi Jews. In particular, if such a pattern emerges, does it show any overlap with the pattern of alpha-actinin-3 deletion, another gene I wrote about before, a muscle component that is more likely than even odds to be deleted in female distance runners (and non-Africans) but less likely than even odds to be deleted in sprinters and weight-lifters.