An example of how this might work is provided by the studies of Pavio and colleagues [38], where HCV core variants isolated from hepatocellular carcinoma cells differed, in a highly significant fashion, in ability to modulate the TGFbeta response pathway, which is critical for maintenance of cell differentiation, compared to HCV core isolated from adjacent, non-cancerous liver. The gene discussed is TGFB1; the disease is hepatocellular carcinoma.