Spatial omics refers to the ability to measure the activity of biomolecules (RNA, DNA, proteins, and other omics) in situ--directly from tissue samples. This is important because many biological processes are controlled by highly localized interactions between cells that take place in spatially heterogeneous tissue environments. Spatial omics allows previously unobservable cellular organization and biological events to be viewed in unprecedented detail. A few years ago, these technologies were just prototypes in a handful of labs around the world. They worked only on frozen tissue and they required impractically large amounts of precious tissue biopsies.