Age matched MMTV-neu, MMTV-ζ.neu and WAP-ζ.neu mice. A,B, Quantitative analysis of Ki-67-positive nuclei (left) and representative Ki-67 IHC (right) showed significant increase in Ki-67 positive staining in bitransgenic MIN lesions (X200, n=13,6,6) and tumors (X400, all n=9) compared to MMTV-neu. C,D, Quantitative analysis of p27-positive nuclei (left) and representative p27 IHC (right, X200) showed significant decrease in p27 positive staining in bitransgenic MIN lesions and tumors compared to MMTV-neu (all n=9).