To further examine the effects of chronic alcohol exposure on renal fibrosis, we determined the mRNA and protein expression levels of several fibrosis-related genes, including Col I, TGFβ, CCN2 and CCN3. We found that 2 weeks of the 4.5% alcohol diet treatment did not induce the mRNA or protein expression of Col I, TGFβ, CCN2 and CCN3 compared with the normal diet treatment (Figures 4a–c). Here, TGFB1 is linked to renal fibrosis.