This transgenic strain was established by CLEA Japan, Inc. The construct is as follows: CAG promoter, loxP sequence, neomycin resistance gene, loxP sequence and Ha-ras*G12V (HrasV12). It was injected into Jcl:SD embryos, the transgene is regulated by the Cre/loxP system. Human Ha-ras*G12V oncogene is driven by CAG promoter