EGFR and neoplasm: We hypothesized that the enhanced expression of mesenchymal proteins and, in particular, the high expression of CSC-associated markers and function in tumor cells treated with erlotinib for 72 h could be a consequence of either (1) selection of a small population of cells that previously exhibited features of EMT/CSCs in the parental cell line, or (2) induction of tumor cells into an EMT/CSC status following blockade of EGFR signaling.