Evaluation of immunohistochemically stained serial sections showed a strong positive correlation of MMP-1 expression with proliferating cells (Figure 3a and 3b: MMP-1+/Ki-67+: r = 0.943 for BE, n = 41 and r = 0.811 for EAC, n = 60). The gene discussed is MMP1; the disease is Barrett esophagus.