Representative H+E sections of mammary tumors from progeny females of the MMTV-Wnt-1 and Pten+/- cross. Sections were from tumors that were Wnt-1 TG+, Pten+/+ (A); Wnt-1 TG+, Pten+/- (B); and Wnt-1 TG+, Pten+/- with LOH (C and D). A 40x objective was used. Blue arrows indicate the smooth boundaries of tumors, red arrow marks the infiltrating front of the tumor, and white arrows label the highly cellular stroma. (D) shows a part of an intraductal squamous lesion.