Recent proteomic and single-cell advances are transforming understanding of human aging, disease, and cellular heterogeneity. A comprehensive study revealed protein expression shifts accelerating organ aging near age 50, especially in blood vessels. Single-cell immune profiling by Omniscope offers promising tools for monitoring cancer immunotherapy responses. Spatial proteomics, recognized as Nature’s 2024 Method of the Year, is enhancing precision oncology and disease progression insight through initiatives like the Human Protein Atlas. Additionally, large-scale single-cell genomics projects are revolutionizing cell mapping, facilitating understanding of cell communications and heterogeneity in cancer, neuroscience, and immunology.