While many technologies focus on either exploring the spatial context of a handful of targets, or expression patterns of hundreds or thousands of targets in bulk samples or dissociated single-cells, the GeoMx Cancer Transcriptome Atlas (CTA) for use with the GeoMx DSP blends high-plex and spatial analysis in a single experiment. GeoMx DSP enables spatially resolved, digital characterization of proteins or mRNA in a highly multiplexed (>1,000-plex) assay. The assay relies upon antibody or RNA probes coupled to photocleavable oligonucleotide tags called DSP barcodes. After hybridization of probes to slide-mounted tissue sections, the DSP barcodes are released from discrete regions of the tissue via UV exposure. Released tags are quantitated via sequencing, and counts are mapped back to tissue location, yielding a spatially-resolved digital profile of analyte abundance. CTA uses the RNA probes described above and has been designed with the spatial context of cancer biology in mind, to enable studying key facets of disease without compromising sensitivity or specificity in Formalin Fixed Paraffin Embedded (FFPE) and fresh frozen tissues.