For the first time, scientists have succeeded in genetically engineering a rat by specifically removing a single gene,  reported online August 11 in Nature. The process is known to geneticists as “knocking out” a gene; in this case, the gene encodes a powerful anticancer protein known as p53.

Rats lacking the gene p53, which are likely to be used to study cancer and its treatment, will be available to researchers through a resource center at the University of Missouri in Columbia.