EASE (Expression Analysis Systematic Explorer) is a software tool designed to rapidly interpret gene lists derived from microarray, proteomics, and SAGE data. It identifies biological themes within these lists by mapping gene identifiers to a standardized gene accession system and then mapping genes to various classification systems. EASE performs three main functions: theme discovery, customizable linking to online tools, and creation of descriptive annotation tables. The software uses a Fisher exact probability test with an adjusted EASE score to identify over-represented gene categories. EASE has been shown to recapitulate manually determined themes from published studies and is robust to varying methods of gene selection and normalization. It offers several advantages over similar software, such as MAPPfinder and GoMiner, including ease of use, the ability to load genes into online tools, and the generation of detailed annotation tables. EASE is freely available for non-profit researchers and has been applied in various biological studies, demonstrating its utility in interpreting high-throughput genomic data.EASE (Expression Analysis Systematic Explorer) is a software tool designed to rapidly interpret gene lists derived from microarray, proteomics, and SAGE data. It identifies biological themes within these lists by mapping gene identifiers to a standardized gene accession system and then mapping genes to various classification systems. EASE performs three main functions: theme discovery, customizable linking to online tools, and creation of descriptive annotation tables. The software uses a Fisher exact probability test with an adjusted EASE score to identify over-represented gene categories. EASE has been shown to recapitulate manually determined themes from published studies and is robust to varying methods of gene selection and normalization. It offers several advantages over similar software, such as MAPPfinder and GoMiner, including ease of use, the ability to load genes into online tools, and the generation of detailed annotation tables. EASE is freely available for non-profit researchers and has been applied in various biological studies, demonstrating its utility in interpreting high-throughput genomic data.