I think the biggest bit of positive news in this fascinating study is mentioned just in passing...that the treated mice "developed Cancer later".

In a lot of Aging related research tinkering, very often there are steep costs to improving life-spans - increased rates of Cancer. See anytime you mess with the reason a Cell lives or dies due to ageing, you are risking higher Cancer rates. The fact that this treatment both improves life-spans and "delays cancer" is indeed very promising. Now hopefully the transmission pathways hold true in Humans...