Anti-K5 antibody staining furthermore revealed that the few LacZ+ cells in HF and HF-near IFE of DMBA/TPA-treated R26-LacZ Ptchf/f CD4Cre skin are positive for K5 or at least descend from K5+ cells (e.g., suprabasal layers of the IFE) (Figure 6D). The gene discussed is KRT5; the disease is hydrops fetalis.