Reflect On 20 Years Of Cancer Research With MIRROR Biospecimens

By Kaylee Mueller

The MIRROR cohort represents a unique opportunity to revisit some of the most influential tumors in modern oncology, bringing together the “twin” tissue blocks from the expO project and The Cancer Genome Atlas (TCGA). Built from specimens originally collected nearly two decades ago, MIRROR reconnects physical biospecimens with the digital datasets that helped define precision medicine. Its foundation lies in the evolution of cancer genomics: expO’s openly shared microarray data laid the groundwork for TCGA’s multi-omic enterprise, which in turn has fueled tens of thousands of studies and reshaped scientific understanding across dozens of tumor types. But while TCGA’s data remain widely accessible, many of the original tissues have long been depleted—until now.

MIRROR restores access to these historical tumors, enabling researchers to interrogate them with technologies that did not exist when they were first analyzed, including spatial biology, proteomics, liquid biopsy assays, and AI-driven pathology. By pairing annotated tissue and biofluids with legacy genomic and clinical datasets, MIRROR creates a bridge between past and present, giving scientists the ability to ask entirely new questions of well-studied samples and to explore biological insights that were once beyond reach.