In one aspect, the invention provides a transgenic non-human animal model having germ cells and somatic cells containing an endogenous MMTV-SV40-Spy1A gene sequence introduced into said animal model or an ancestor of said animal model at an embryonic stage, wherein said gene sequence comprises a mouse mammary tumor virus gene (MMTV), a functionally disrupted SV40 gene (SV40) and a human Spy1A gene. In another aspect, the present invention provides a transgenic non-human animal model whose germ cells and somatic cells contain an endogenous Spy1A-pTRE-Tight gene sequence introduced into said animal model or an ancestor of said animal model at an embryonic stage. Preferably, the Spy1A-pTRE-Tight animal model expresses the Spy1A gene and develop cancer, preferably breast cancer, when administered with tetracycline, preferably doxycycline.
