SAG and hepatocellular carcinoma: Gankyrin is known to contribute to the development of HCC by eliminating tumor suppressors p53, Rb and C/EBPa.21,22 In addition to gankyrin, there are other UPS components that are also highlighted in HCC, including Siah1 and Parkin.23,24 Thus, the complexity of UPS components, including SAG, may exert multiple and simultaneous roles during HCC development.