Science progress

[LifeIsStrange]

From https://lemire.me/blog/

In mammals, the heart does not regenerate. Dead heart cells are dead and no replacement is produced. New research shows that this can be changed, in mice, by pumping them up with a small molecule called miR-294. The treated mice saw good heart regeneration.
In human beings, an important part of the immune system, the thymus, simply disappears over time, leaving older people with a weaker immune system. In mice, this can be reversed using transgenic exosomes.