Generation of ENU mice and housing.
ENU mutagenized C57BL/6 mice were generated as described [19]. Mice were maintained by backcrossing affected animals to C57BL/6 and housed in the Genomics Institute of the Novartis Research Foundation Specific Pathogen Free animal facility (La Jolla, California, United States). All procedures were approved by the Genomics Institute of the Novartis Research Foundation Institutional Animal Care and Use Committee.