Fig. 5. Ectopic proliferation of differentiated Rb-deficient keratinocytes. (A-C,E,F) Double immunofluorescence against BrdU (green) and K10 (red) in the epidermis of adult Rb^F19/F19 (A), Rb^F19/F19;K14cre (B) and Rb^F19/F19;p107^+/–;K14cre mice (C); and in Rb^F19/F19 (E) Rb^F19/F19;K14cre (F) primary keratinocytes upon 24 hours of Ca²⁺-induced differentiation. Arrows indicate BrdU incorporation in K10-expressing cells. (D) Triple immunofluorescence against K5 (red), K10 (blue) and BrdU (green) showing BrdU incorporation in cells expressing K10, but not K5 (arrows). (G) Summary of the BrdU incorporation in K10-positive primary keratinocytes of the indicated genotypes. Data are from the analysis of three independent experiments scoring at least 500 cells. White lines in A-C indicate the dermal epidermal junction. Scale bars: 50 µm.