Figure 6.

 Effects of cytokines on the raft culture constructed with human foreskin keratinocyte (HFK)_p18FLneo. Effects of cytokine treatments on the raft culture organized with normal HFKs or HFK_p18FLneo were examined. Frozen‐sections of the raft culture were fixed with 4% paraformaldehyde and stained with H&E. The thickness of the epidermis was estimated by microscopic analysis with an image analysis application (AxioVision; Carl Zeiss Vision), and the relative values are indicated as a bar chart (thickness of not treated normal HFK set as 1.0; average value, 95 μm). The value is the average of at least three independent experiments and the SD is indicated. Note that the epidermis of the HFK_p18FLneo treated with tumor necrosis factor (TNF)‐α exhibited the invasion phenotype; therefore, the thickness of it could not be measured precisely (indicated with an asterisk).