John Dick, Ph.D., F.R.S., explores the role of CD83, a molecule found in blood stem cells, in how these cells respond to inflammation. His team demonstrates that CD83 becomes highly active during inflammation and contributes to the loss of healthy stem cells. Using advanced gene-editing tools, they show that removing CD83 protects stem cells from inflammation-related damage. This discovery highlights CD83 as a potential marker for identifying inflamed stem cells and as a possible target for treatments to improve recovery after stem cell transplants. He also discusses early findings on potential differences in blood stem cell behavior between men and women and raises questions about how inflammation from severe illnesses, like COVID-19, could impact the blood system as we age. (#39949)