We should point out that in contrast to the DMBA/TPA model where TCF7L1 overexpression increased proliferation of epidermal cells in skins that have yet to become papilloma but not in the papilloma themselves, in a xenograft model overexpression of TCF7L1 increased proliferation of SCC cells in vivo (Figure 4C,D). The gene discussed is TCF7L1; the disease is papilloma.