– Gankyrin is a multicatalytic proteinase oncoprotein consists of 7 ankyrin repeats. Gankyrin overexpressed in most hepatocellular carcinomas. Gankyrin is involved in theregulation of the phosphorylation of the retinoblastoma protein by CDK4 to enhance the ubiquitinylation of p53 by MDM2. Gankyrin is also involved in progression of esophageal squamous cell carcinoma. Gankyrin plays an oncogenic role especially in early stages of human epatocarcinogenesis.