SNAI1 and lung carcinoma: To recapitulate the EMT process in tissue culture, we engineered the lentiviral-mediated, doxycycline (Dox)-inducible overexpression of Snail in the A549 cells, a lung carcinoma cell line that has been widely used as in vitro model for EMT.[25] As shown in Figure 1, Dox treatment of the stable infectants, designated as the A549-Snail cells, strongly induced the expression of Snail protein in the nuclei, as examined by the Western blotting and immunohistochemistry.