The Gene Expression Omnibus (GEO) database, established at the National Center for Biotechnology Information (NCBI) a decade ago, has evolved from a repository for high-throughput gene expression data to a comprehensive archive for functional genomics studies. Initially focused on microarray technology, GEO has adapted to include non-gene-expression studies and next-generation sequencing data. Today, it stores over 20,000 studies with 500,000 samples and 33 billion individual abundance measurements, supporting over 10,000 published manuscripts. The database's flexible structure allows for the storage of diverse data types, and it provides robust tools for searching, browsing, downloading, and visualizing data. Recent enhancements include new search and data representation tools, as well as improved indexing and analysis capabilities. GEO continues to be a crucial resource for researchers, facilitating data integration, cross-comparison, and innovative applications in various fields of genomics.The Gene Expression Omnibus (GEO) database, established at the National Center for Biotechnology Information (NCBI) a decade ago, has evolved from a repository for high-throughput gene expression data to a comprehensive archive for functional genomics studies. Initially focused on microarray technology, GEO has adapted to include non-gene-expression studies and next-generation sequencing data. Today, it stores over 20,000 studies with 500,000 samples and 33 billion individual abundance measurements, supporting over 10,000 published manuscripts. The database's flexible structure allows for the storage of diverse data types, and it provides robust tools for searching, browsing, downloading, and visualizing data. Recent enhancements include new search and data representation tools, as well as improved indexing and analysis capabilities. GEO continues to be a crucial resource for researchers, facilitating data integration, cross-comparison, and innovative applications in various fields of genomics.