Clinical evidence demonstrates that RPE cells undergo epithelial-to-mesenchymal transition (EMT) in AMD [20–22], and the level of transforming growth factor-β (TGF-β), an inducer of EMT, is elevated in the retina of patients with AMD compared with that in normal control eyes [23, 24], suggesting that transplanted RPE cells derived from MSCs are very likely to undergo EMT, subsequently reducing the therapeutic effect of transplanted cells. The gene discussed is TGFB1; the disease is age-related macular degeneration.