These Cdk5 floxed mutant mice possess loxP sites flanking exons 1-5. Mice that are homozygous for this allele are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. When bred to mice that express Cre recombinase, resulting offspring lack detectable Cdk5 in the cre-expressing tissues. The Jackson Laboratory 2024, used with permission.