Despite a year marked by budget cuts and shrinking research teams, science delivered some remarkable wins in 2025. Breakthroughs across medicine reshaped how we understand human health—and, in some cases, changed how care is provided today. Scientists uncovered surprising new ways to prevent diseases and to boost cancer treatments. They’ve created an atlas of the human body, edited a gene for a single child, and improved care for conditions ranging from food allergies to menopause to cervical cancer and human immunodeficiency virus (HIV). These are nine of the year’s most impressive discoveries.