In addition, primary HCC cells have been shown to secrete EVs containing both SMAD Family Member 3 (SMAD3) protein and mRNA, which when delivered to recipient circulating HCC cells, regulate circulating tumour cell proliferation and adhesion and promote lung metastasis via the SMAD3‐reactive oxygen species (ROS) signalling pathway (Fu et al., 2018) (Figure 1b). The gene discussed is SMAD3; the disease is hepatocellular carcinoma.