FACS analysis of CK 19 expression. (A and B) SSC/FSC plots of all cells in WT (A) and ERβ-/- (B) samples, with areas r1 and r2 gated according to the size and granularity. (C and D) Gated areas on FITC–CK 19 histograms corresponding to A and B (blue, WT; red, ERβ-/-). WT (E) and ERβ-/- (F) SSC/FSC plots of CK 19-positive cell populations from areas gated r1 and r2 in B and C; g1–g3 areas representing possible localization of basal, intermediate, and luminal cells, respectively.