Model Description: A 2A-EGFP-Cre expression cassette was knocked into the Calb1 gene stop codon site. Calb1 is highly expressed in the brain. When crossed with a strain carrying a gene flanked by loxP sites, the flanked gene will be removed in cells expressing Cre. This strain is useful in studying many neurobehavioral diseases such as spatial learning and circadian rhythm interference. It has been reported that the incidence of many diseases may be different between genders.