Eric Topol, MD

has a nice summary of the two back-to-back landmark papers on thymic health published in Nature (https://lnkd.in/ePyWdTAM and https://lnkd.in/emcmz5iu) last week by a team led by Hugo Aerts. It is a big deal in many ways, in particular because they show that a well-functioning thymus seems to be important as we age, not just in our early years. Even if it is only as a marker and not a causal mechanism, it is a big step forward given the associations uncovered between thymic health and many diseases of aging. I want to focus on one caveat of these studies (which again I think are spectacular in their depth and scope): Thymic health is estimated primarily through the size of the thymus. It is a reasonable and clinically accessible proxy but it does raise the question of the composition of the thymus in its two distinct subregions. The fact that size is such a strong predictor of a range of outcomes is mind blowing.