Previous studies of molecular mechanisms underlying the massive foveolar hyperplasia observed in a mouse model of Ménétrier’s disease (transforming growth factor α [TGFα]) showed that overexpression of TGFα and stimulation of the epidermal growth factor-receptor (EGFR) promoted isthmal progenitor cell differentiation preferentially into foveolar cells.8 The gene discussed is TGFA; the disease is gastric mucosal hypertrophy.