MMP9 and cancer: Lan et al., [184] reported a dose- and time-dependent reduction in cell migration and invasion in human HOS and MG-63 cell lines, which was paralleled with a significant quercetin-induced downregulation of the expression of HIF-1α and downstream genes, such as, VEGF, MMP-2, and MMP-9, which play essential roles in promoting cancer invasion and metastasis.