A. Immunofluorescence of ear lesions formed by SCC13 cells with HDFs plus/minus shRNA-mediated silencing of PDCD4 with antibodies against Ki67 and Vimentin (upper panels) or Involucrin and p63 (lower panels). Shown are representative images as well as a quantification of Ki67, p63, and involucrin staining. Percentages of Ki67 positive nuclei in Vimentin negative SCC cells were quantified by Adobe Photoshop software using Lasso tool in three different fields from 3 ear pairs. p63 positive nuclei over total nuclei were quantified using Image J. * < 0.05, ** < 0.005, two-tailed t-test. Bar, 100μm. B. Immunofluorescence analysis of ear lesions formed by SCC13 cells with HDFs plus/minus shRNA-mediated silencing of PDCD4 with antibodies against Loricrin with DAPI for nuclear staining. Positive areas relative to entire lesion size (expressed as %) were quantified using Image J software. * < 0.05, two-tailed t-test, Bar, 100μm. C. Immunofluorescence analysis of ear lesions formed by SCC13 cells with HDFs plus/minus shRNA-mediated silencing of PDCD4 with antibodies against Periostin (POSTN), Tenascin C (TNC), and α-Smooth muscle actin (ACTA2)with DAPI for nuclear staining. Shown are representative images as well as quantification of positive areas relative to entire lesion size (expressed as %) in 3 different fields from 3 ear pairs using Image J software. * < 0.05, two-tailed t-test, Bar, 100μm.