A new study from the Allen Institute compares human brain cells’ molecular features to those of the marmoset monkey and mouse in a region of the brain that controls movement, the primary motor cortex. Using a technique known as single-cell transcriptomics, the researchers compared the suite of genes each individual brain cell switches on, across thousands of cells from each of the three species. Shown here, transcriptomic data clustered by type of brain cell, in the human (left), marmoset monkey (middle), and mouse brain (right). Credit: Allen Institute