The Wellcome Trust Sanger Institute is a genome research institute primarily funded by the Wellcome Trust. It uses large-scale sequencing, informatics and analysis of genetic variation to further understand the gene function in health and disease and to generate data and resources of lasting value to biomedical research. It focuses on using natural and experimental variation as an approach, and genetic manipulation of the mouse genome is a key activity. The Wellcome Trust Sanger Institute has a significant library of gene-trap ES cells (SIGTR) and a mouse clone library (MICER) that are available to researchers on request. The Wellcome Trust Sanger Institute is partner in the EUCOMM (EC); KOMP (NIH); European Mouse Mutant Archive (EMMA) and one of the primary phenotyping centres of the EUMODIC (EC) programme.