Researchers have created a taxonomy of microglia, a type of brain cell, across various mouse and human pathologies. This work involves the use of single-cell transcriptomics and other techniques to map and understand the function and heterogeneity of microglia in health and disease, including neurodegenerative conditions such as Alzheimer's disease. The studies aim to decipher the complexity of brain diseases and identify changes in disease-associated microglia subsets.