The Gene Expression Omnibus (GEO) at the National Center for Biotechnology Information (NCBI) is the largest public repository for high-throughput gene expression data. It also hosts other categories of high-throughput functional genomic data, including genome copy number variations, chromatin structure, methylation status, and transcription factor binding. The database is flexible and can capture fully annotated raw and processed data, adhering to major scientific reporting standards such as 'Minimum Information About a Microarray Experiment' (MIAME). GEO offers tools and features for users to explore, analyze, and download data from both gene-centric and experiment-centric perspectives. The repository has grown to include over 10,000 experiments, 300,000 samples, and 16 billion individual abundance measurements from 500 organisms and 5000 laboratories worldwide. Recent developments include the introduction of a new division called 'Omix' for non-expression data, and the processing of high-throughput sequence data. The GEO database is freely accessible and continues to evolve to enhance the experiences of both data submitters and consumers.The Gene Expression Omnibus (GEO) at the National Center for Biotechnology Information (NCBI) is the largest public repository for high-throughput gene expression data. It also hosts other categories of high-throughput functional genomic data, including genome copy number variations, chromatin structure, methylation status, and transcription factor binding. The database is flexible and can capture fully annotated raw and processed data, adhering to major scientific reporting standards such as 'Minimum Information About a Microarray Experiment' (MIAME). GEO offers tools and features for users to explore, analyze, and download data from both gene-centric and experiment-centric perspectives. The repository has grown to include over 10,000 experiments, 300,000 samples, and 16 billion individual abundance measurements from 500 organisms and 5000 laboratories worldwide. Recent developments include the introduction of a new division called 'Omix' for non-expression data, and the processing of high-throughput sequence data. The GEO database is freely accessible and continues to evolve to enhance the experiences of both data submitters and consumers.