To further clarify the effect of TGF-β1 on BMAL1 expression, we investigated the expression level of BMAL1 in response to TGF-β1 in three different lung cell lines, including epithelial cells (normal lung epithelial cell line HPL1D and human lung adenocarcinoma epithelial cell line A549) and normal human lung fibroblasts (NHLFs). This evidence concerns the gene TGFB1 and lung adenocarcinoma.