Consistent with these findings, our results showed that the expression of TGF‐β, Smad2, Ser423/425‐phosphorylated Smad3, and Smad4 was remarkably increased in livers of HBx transgenic mice compared with non‐transgenic mice from the early time points (4 h, 12 h, 3 days, and 10 days) to the late time points (3 months) even up to tumor formation after PH in comparison with the age‐matched non‐PH mice. Here, SMAD4 is linked to neoplasm.