In addition, MMP9 expression was significantly decreased following curcumin and genistein administration alone and in association as already demonstrated in several papers that investigated their anti-proliferative effects both in vitro and in vivo [53,54] Generally, cancer cells frequently exhibit increased levels of ROS, which can have both tumor-promoting and tumor-suppressing effects depending on their concentration and the cellular environment [55]. This evidence concerns the gene MMP9 and neoplasm.