Since overexpression of TCF7L1 did not stimulate proliferation of DMBA/TPA induced papilloma per se and did not promote tumor development without DMBA treatment (Figure 2—figure supplement 3C), it suggests that TCF7L1 may facilitate the transitioning of DMBA-induced mutated cells into premalignant tumors. The gene discussed is TCF7L1; the disease is neoplasm.