However, the high proportion of HCC patients with viral etiology, with the expression of the viral protein HBx, leading to multistep degradation of Smc5/6 proteins involved in DSB repair, may mean that these patients receiving dual therapy (e.g., PARPi + RT) respond much better than HCC patients with other liver cancer etiologies. The gene discussed is SMC5; the disease is hepatocellular carcinoma.