Zebrafish embryonic and transgenic adult methods have also shown that the tyrosine kinase inhibitors, 419S1 and 420S1, have comparable or superior effects against HCC angiogenesis and migration than the FDA-approved broad-spectrum protein kinase inhibitor HCC drug, sorafenib, and lower toxicity, with 419S1 and 420S1 having a suppressive effect on the cell cycle genes, ccne1, cdk1, and cdk2, as did sorafenib [160]. The gene discussed is CDK1; the disease is hepatocellular carcinoma.