Tumour buds may have a role in ECM degradation, a hypothesis supported by increased immunohistochemical expression of proteins such as matrix metalloproteinases MMP-2 and MMP-9, and urokinase plasminogen-activator receptor (uPAR) in high-grade tumour-budding cases (Zlobec and Lugli, 2010). The gene discussed is MMP9; the disease is neoplasm.