I can't read the article but there's no explanation for why they would be interested in isoleucine in particular. They also seem nonplussed as to the mechanisms

I can't read the article but there's no explanation for why they would be interested in isoleucine in particular. They also seem nonplussed as to the mechanisms of any isoleucine-restriction longevity. As a result it comes across very post hoc. I suspect I'm missing something though?