SMAD4 and hepatocellular carcinoma: Lin et al. [112] demonstrated that high levels of miR-210-3p in the serum of patients with HCC are correlated with higher microvessel density and thereby promote tumor angiogenesis by targeting SMAD4 and STAT6. Serum exosomal miR-638 in HCC patients is negatively associated with tumor size, vascular infiltration, and TNM stage [113].