RB1 and ovarian cancer: Our results are supported by several lines of evidence indicating that ginseng inhibits MMP-2 and MMP-9 expression and activity; GE suppresses the metastasis of human hepatoma SK-Hep1 cells by inhibiting MMP-2 and MMP-9 [19], and GSs including Rb1, Rb2, Rd, and Rg3 inhibit MMP-2 and MMP-9 protein expression and activity in several types of cells such as SKOV-3 ovarian cancer cells and HepG2 human hepatoma cells [15–18, 30, 31], suggesting that the inhibition of MMP activity is important in terms of preventing cell metastasis.