MMP1 and neoplasm: Therefore, tumor cells destroy the normal connection of vascular endothelium by secreting protein angiopoietin-like 4 (Angptl4) and various cytokines, such as cyclooxygenase-2 (COX-2), epiregulin (EREG), and MMP-1/2, thereby promoting the extravasation of tumor cells (Padua et al., 2008; Gupta et al., 2007a).