Experts from the Chan Zuckerberg Initiative and Wellcome Sanger Institute highlighted breakthroughs in single-cell RNA sequencing that are transforming biomedical research. Increasing project scales enable detailed cell mapping across tissues, advancing understanding in cancer, neuroscience, and immunology. This granularity uncovers cellular heterogeneity and disease mechanisms, fostering novel therapeutic targets and personalized medicine approaches. The ongoing expansion of single-cell technologies promises paradigm shifts in life sciences research.