By using array-based sequence capture and pyrosequencing to sequence an allelic series from the classically defined Kit locus (~200 kb) from each of five noncomplementing Kit mutants (one known allele and four unknown alleles), D'Ascenzo and co-workers discovered and validated a nonsynonymous coding mutation for each allele. These data represent the first documentation and confirmation of the fact that the new technologies can be used to efficiently discover causative mutations. Importantly, these results also provide the framework for constructing the efficient detection of causative mutations in mutant mouse strains moving forward. The standards presented here, coupled with the latest sequence capture methods (e.g., whole-exome arrays or solution-based methods) and next-generation sequencing technologies, promise to signicantly close the gap between phenotype and genotype in the mouse more