BMAL1 and lung adenocarcinoma: 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).