How healthy am I? My immunome knows the score. Made up of 1.8 trillion cells and trillions more proteins, metabolites, mRNA, and other biomolecules, every person's immunome is different, and it is constantly changing. It's shaped by everything we have ever been exposed to physically and emotionally, and powerfully influences everything from our vulnerability to viruses and cancer to how well we age to whether we tolerate certain foods better than others. Yet as critical as the immunome is to each of us, it has remained largely beyond the reach of modern medicine. Now, thanks to a slew of new technologies, understanding this vital and mysterious system is within our grasp, paving the way for powerful new tools and tests to help us better assess, diagnose and treat diseases. On Monday, we published our 2025 edition of Climate Tech Companies to Watch .

How healthy am I? My immunome knows the score. Groundbreaking new tests reveal patterns in our immune systems that can signal underlying disease and tell us how well we might recover from our next cold. I got my results in a text message. It's not often you get a text about the robustness of your immune system, but that's what popped up on my phone last spring. Sent by John Tsang, an immunologist at Yale, the text came after his lab had put my blood through a mind-boggling array of newfangled tests. The result--think of it as a full-body, high-resolution CT scan of my immune system--would reveal more about the state of my health than any test I had ever taken. And it could potentially tell me far more than I wanted to know. "David," the text read, "you are the red dot." Tsang was referring to an image he had attached to the text that showed a graph with a scattering of black dots representing other people whose immune systems had been evaluated--and a lone red one.