alignments between assemblies to facilitate comparative and evolutionary investigations. The heavily annotated human genome offers extensive conservation and evolutionary comparisons, a large collection of gene models including the locally generated UCSC Genes track (6,7), regulation, expression, epigenetics and tissue differentiation, variation, phenotype and disease association data, and data that have been text-mined from publications. Much of our annotation data is obtained through external collaboration. When available, links are provided to the complementary annotations in the Ensembl and NCBI browsers, and to supplementary information on other websites.
