It was found that both belinostat and Cubisbel significantly inhibited HDAC activity in all three colon cancer cell lines (SW480 P = 0.009 and 0.0018; SW620 P = 0.0004 and < 0.0001; CACO-2 P = 0.0018 and < 0.0001 respectively) (Fig. 2a), with greater significance observed with treatment of Cubisbel. Here, HDAC9 is linked to malignant colon neoplasm.