Shikonin suppressed tumor cell proliferation in HCC, LM3, SMMC-7721, Huh-7 and HepG2 cells via reducing the expression of PKM2 and cyclinD1, resulting in a decrease in PKM2 expression and the binding of PKM2 to Bcl-2, inducing apoptosis in HCC cells (Liu et al., 2020b). The gene discussed is CCND1; the disease is hepatocellular carcinoma.