Notably, TGF-β is known to have two opposite effects on tumor progression; it functions as a tumor suppressor through proliferation inhibition of nontransformed cells, and it promotes tumor progression of transformed cells by inducing an epithelial–mesenchymal transition (EMT), which results in destabilization of cell–cell adhesions, acquisition of spindle cell morphology, formation of stress fibers, and enhancement of cell motility (2). The gene discussed is TGFB1; the disease is neoplasm.