RT-qPCR and IHC results showed that the expression level of SMAD4 in liver tissues of CCl4-induced HF mice was significantly higher than that in Control mice; and overexpression of miR-324-3p through transfection of AAV-miR-324-3p could significantly reduce the expression of SMAD4 in liver tissues of CCl4-induced HF mice (Fig. 7A, B, C). The gene discussed is SMAD4; the disease is hydrops fetalis.