Fig. 1

High-dimensional analysis of the diseased CSF. A Schematic illustration of the brain parenchyma, the cerebrospinal fluid (CSF), the meninges, and the skull. Immune cells can migrate from the skull bone marrow through skull channels to the dura layer of the meninges, where they accumulate in the vicinity of dural sinuses. Main findings of single-cell transcriptomics studies of the CSF are visualized in the upper right, including cytotoxic T cells and clonal expansion of B and T cells in inflammatory diseases, cancer cells with iron-binding protein/protein and adhesion molecules in tumors, and clonally expanded T cell in neurodegenerative disorders (see Table 1 and main text for details). B Potential future applications. We envision that cell patterns and the transcriptomic profile of CSF single-cell analysis will be utilized in the future to train machine learning algorithms to predict the clinical outcome, support differential diagnosis and permit a personalized therapy.