In addition, it has been shown that Rac1 interacted directly with p67phox, which in turn contributed to the assembly of NADPH oxidase complexes, resulting in the production of ROS.40,41 Based on these observations, we speculated a positive-feedback loop developed between ROS levels and Rac1 activity in HBV-associated HCC during detachment. The gene discussed is FMO5; the disease is hepatocellular carcinoma.