PES-ERαKO mice fail to respond to DES treatment. H& E staining (A) and IHC staining of CK10 (B) from Wt, ACTB-ERαKO, FSP-ERαKO, and pes-ERαKO AP tissue treated with vehicle (cholesterol) or DES. Note that DES treatment in Wt and FSP- ERαKO mice resulted in uniform stratified basal epithelial layer, in which squamous epithelial marker, CK10, is expressed (A and B, e and g), but not in the DES treated ACTB- ERαKO and pes- ERαKO mice (A and B, f and h).