Cancer-prone mice transgenic for the rat or human ErbB2 provide more significant models, since their development of an autochthonous tumor recapitulates several of the molecular and genetic features of the progression of human cancer: slow progression, the natural occurrence of invasion and metastasis, and the presence of a long-lasting interaction between the evolving tumor and the host immune system [26]. This evidence concerns the gene ERBB2 and neoplasm.