TP53 and colonic neoplasm: To address whether the anti‐proliferative and apoptotic effects of acetylshikonin on colon cancer cells are dependent on intracellular p53, we treated HCT‐116 p53+/+ (p53 wild type) and HCT‐116 p53−/− (p53 deficient) colon cancer cells with various concentrations (0, 1.25, 2.5, 5, or 10 μM) of acetylshikonin for 24, 48, or 72 hr (Figure 6).