In giant cell carcinoma and prostate carcinoma cells, berberine also decreased G0/G1 phase-associated cyclins (D1, D2, E, Cdk2, Cdk4, and Cdk6), inducing G0/G1 arrest and suppressing cell proliferation [21, 25, 30, 32]. The gene discussed is CDK4; the disease is prostate carcinoma.