Retroviruses are used to construct colorectal tumor cells that can stably express Notch-1 intracellular domain (NICD-1) in the cytoplasm, and the Notch ligand Jagged-1 and CD44, Slug, Smad-3 and other EMT-related proteins are found to be upregulated in these CRC cells.157 Further treatment of the cells with γ-secretase inhibitor DAPT can effectively inhibit this process. The gene discussed is SNAI2; the disease is colorectal carcinoma.