ERβ immunostaining in TRAMP mice. Mice were euthanized at 5 months, and prostates were analyzed for ERβ immunostaining. Normal prostates from non-TRAMP mice were stained as control. A, PIN lesion. B, WDC lesion. C, PDC lesion. D, Plot of IHC scores. n = 49, from studies 1, 2, 6, and 7 (see Supplemental Table 2). ERβ expression did not significantly change with tumor progression. Scale bar, 20 μm. Inset in A shows negative control with specific blocking peptide.