SMAD7 and vitamin A deficiency: Compared to the control group, vitamin A deficiency down-regulated Hamp (2.3-fold, p < 0.001) and Smad7 (1.6-fold, p = 0.027) mRNA levels in the liver and up-regulated hepatic Hfe2 (1.2-fold, p = 0.026) and Bmp6 mRNA levels (2.0-fold, p = 0.0013).