Fig. 6

AREG^−/− tumors are less necrotic and tumor cells in papillary regions are less proliferative. a Representative images of H&E (left column) and Ki67 (right column) staining in AREG^+/+ PyMT and AREG^−/− PyMT 1-cm tumors. Scale bar shows 500 μm for H&E stains and Ki67 stains. b Percentage of necrotic areas calculated as average of five fields per AREG^+/+ (N = 32) and AREG^−/− (N = 22) 1-cm tumors. c, d Ki67⁺ proliferating cells in solid vs papillary areas in 1-cm AREG^+/+ PyMT and AREG^−/− PyMT tumors compared using HistoQuant. Evaluation performed on at least five separate areas from at least three different tumors per genotype. Statistical analysis performed using t test. *p < 0.05, ***p < 0.001, ****p < 0.0001. AREG amphiregulin, H&E hematoxylin and eosin, PYMT polyoma middle-T antigen