It gave me a lot of pleasure to read @hattaca and team's paper. So I will do my best to share my (unsolicited) commentary… Have you ever wondered what actually happens inside the ovary as it ages? Not my field, but that biology is super intriguing. Not just fewer eggs, everyone knows that, but what breaks down at the tissue level, between cells, across time? Lan et al. (Nature Aging) mapped the mouse ovary across age using spatial transcriptomics, what genes were active, where, in which cells, in what order. Over 600k spots across 22 ovaries, hundreds of follicles tracked across the estrous cycle. It turns out that aging does not just deplete follicles, but also breaks the timing. In young ovaries, the right cells do the right things at the right moment. In old ovaries, still cycling, this falls apart. Even atresia, the controlled death of follicles that don't make it, becomes dysregulated, debris accumulating rather than clearing. The immune connection is super cool too!. Aging shifts the immune landscape in ways that drive inflammation rather than tissue maintenance, and this starts before cycles even stop. Not my field (because all of them are) but tissue aging is fundamentally about losing coordination, not just losing cells. And you need spatial tools to see it. nature.com/articles/s43587-0…