Multimodal Human Scalp Atlas Defines Cell Landscape and Lineage Architecture In Situ

The study establishes a high-resolution, multimodal atlas of the human scalp by integrating spatial transcriptomics with single-cell RNA-seq and multiomics data. This atlas reveals spatially organized epithelial and mesenchymal states, linking transcriptional programs to chromatin dynamics and lineage trajectories at single-cell resolution. It uncovers human-specific tissue organization principles and new features of hair follicle architecture. The atlas is used to project patient scRNA-seq profiles from alopecia areata and lichen planopilaris, identifying disease-specific perturbations in fibroblasts, epithelial, and immune populations. This work delineates cellular programs associated with non-scarring versus scarring hair loss, highlighting pathways with diagnostic and therapeutic potential, and provides a foundational resource for human hair biology.