MMP9 and neoplasm: Tumours of the most aggressive sarcomatoid subtype showed higher expression of the EMT transcriptional regulators SNAIL, SLUG, TWIST, ZEB1 and ZEB2, and higher expression of the mesenchymal markers vimentin, S100A4, N-cadherin, α-SMA (α-smooth muscle actin) and MMP9 compared with tumours of the biphasic and epithelioid subtypes.