COSMIC is the world's largest database of somatic mutations in cancer, describing millions of mutations across all types of human cancer. All curated mutation data is mapped to GRCh37 & GRCh38 genomes, along with associated gene expression, CpG methylation, structural breakpoint and non-coding variant data. This information is presented in a fully-featured genome browser alongside a number of genomic annotations including genes, ncRNAs, polymorphisms and regulatory domains. This browser can be used to explore COSMIC's genomic information in standard ways, with many data tracks selectable. In addition, subsets of cancer data can be explored, selecting individual tissues, diseases, tumour samples or cell line panels.