Effects of combined activation of β-catenin and vitamin D receptor. Back skin of ∆K5ΔNβ-cateninER transgenic mice was treated with (A) 4OHT alone, (B) 1,25-dihydroxyvitamin D3 analogue alone (Vit D) or (C–L) 4OHT and 1,25-dihydroxyvitamin D3 analogue for 14 days. (A–C) H&E stained sections. (D) Ki67 immunohistochemical staining. (E, F) Histochemical detection of alkaline phosphatase activity (red). (G–L) Immunofluorescence staining of (G–I) CDP (red), (J) (α8 integrin (red), (K) K31 (red), (L) S100A3 (red) and keratin 14 (green), with DAPI nuclear counterstain (blue). Scale bars: 50 µm.