The Catalogue of Somatic Mutations in Cancer (COSMIC) is the most comprehensive global resource for somatic mutations in human cancer, combining curated scientific literature with tumor resequencing data from the Sanger Institute. It includes data from nearly 4800 genes and 250,000 tumors, resulting in over 50,000 mutations. COSMIC provides a Web-based system for data mining, allowing detailed analysis of mutations, gene summaries, and tumor phenotypes. The system is regularly updated and includes data from the Cancer Genome Project (CGP). Users can search by gene, tissue, or mutation type, and explore data through graphical and tabular views. COSMIC also offers precompiled data files for download. The system includes detailed mutation summaries, histograms, and gene fusion data. Users can examine individual mutations, samples, and gene fusions, and access data through various Web interfaces, including a DAS-enabled Ensembl view. COSMIC data can also be accessed via FTP and an Oracle database. The system is designed to provide high-quality, curated data for cancer research, with a focus on mutation nomenclature, tumor classification, and gene function. COSMIC includes data from literature curation and CGP studies, with a focus on mutation frequency, type, and impact on cancer. The system allows for detailed analysis of mutation spectra, gene fusions, and tumor phenotypes, and provides tools for data export and visualization. COSMIC is a valuable resource for cancer researchers, offering a comprehensive view of somatic mutations in human cancer.The Catalogue of Somatic Mutations in Cancer (COSMIC) is the most comprehensive global resource for somatic mutations in human cancer, combining curated scientific literature with tumor resequencing data from the Sanger Institute. It includes data from nearly 4800 genes and 250,000 tumors, resulting in over 50,000 mutations. COSMIC provides a Web-based system for data mining, allowing detailed analysis of mutations, gene summaries, and tumor phenotypes. The system is regularly updated and includes data from the Cancer Genome Project (CGP). Users can search by gene, tissue, or mutation type, and explore data through graphical and tabular views. COSMIC also offers precompiled data files for download. The system includes detailed mutation summaries, histograms, and gene fusion data. Users can examine individual mutations, samples, and gene fusions, and access data through various Web interfaces, including a DAS-enabled Ensembl view. COSMIC data can also be accessed via FTP and an Oracle database. The system is designed to provide high-quality, curated data for cancer research, with a focus on mutation nomenclature, tumor classification, and gene function. COSMIC includes data from literature curation and CGP studies, with a focus on mutation frequency, type, and impact on cancer. The system allows for detailed analysis of mutation spectra, gene fusions, and tumor phenotypes, and provides tools for data export and visualization. COSMIC is a valuable resource for cancer researchers, offering a comprehensive view of somatic mutations in human cancer.